Pestivirus species

ABSTRACT

The application relates to a pestivirus, designated PMC virus, that is associated with porcine myocarditis syndrome, and the gene and protein sequences derived therefrom. The application further relates to detection methods, vaccine therapeutics, and diagnostic methods using the PMC virus or gene/protein sequences derived therefrom.

FIELD OF THE INVENTION

The present invention relates to a novel pestivirus, and gene sequencesderived from the same. The invention further relates to detectionmethods, vaccines, therapeutics, and diagnostic methods using thesequences of the present invention.

REFERENCE TO SEQUENCE LISTING

A Sequence Listing submitted as an ASCII text file via EFS-Web is herebyincorporated by reference in accordance with 35 U.S.C. §1.52(e). Thename of the ASCII text file for the Sequence Listing is 13279926.TXT,the date of creation of the ASCII text file is May 16, 2012, and thesize of the ASCII text file is 110 KB.

BACKGROUND ART

Pestiviruses cause highly contagious and often fatal diseases of pigs,cattle and sheep, which are characterised by damage to the respiratoryand gastrointestinal tracts and immune system and can run an acute orchronic course. Infection of the reproductive system may cause embryonicand foetal death, congenital defects and the birth of persistentlyinfected animals. Outbreaks of the diseases associated with pestivirusinfections occur in many countries and can cause large economic losses.

The Pestivirus genus of the Flaviviridae comprises three structurally,antigenically and genetically closely related member species: Classicalswine fever (CSF) or hog cholera (Francki et al. 1991. Flaviviridae, Inthe Fifth report of the International Committee on Taxonomy of Viruses,Archiv. Virol. Suppl. 2, Springer Verlag, Vienna p. 223-233); Bovineviral diarrhoea virus (BVDV) which mainly affects cattle, and Borderdisease virus (BDV) which mainly affects sheep (Moennig and Plagemann(1992) Adv. Virus Res. 41: 53-98; Moormann et al., (1990) Virology 177:184-198; Becher et al. (1994) Virology 198: 542-551). Recent studiesindicate that there may be several less well recognised viruses thatwarrant separate taxonomic classification, perhaps as separate species(Avalos-Ramirez et al (2001) Virology 286: 456-465)

The genomes of pestiviruses consist of a positive strand RNA molecule ofabout 12.5 kb (Renard et al. (1985) DNA 4: 429-438; Moormann and Hulst(1988) Virus Res. 11: 281-291; Becher et al. (1994) Virology 198:542-551). However, the positive strand RNA genomes of severalcytopathogenic BVDV strains may be considerably larger (Meyers et al.(1991) Virology 180: 602-616; Meyers et al. (1992) Virology 191:368-386; Qi et al. (1992) Virology 189: 285-292).

An inherent property of viruses with a positive strand RNA genome isthat their genomic RNA is infectious, i.e. after transfection of thisRNA in cells that support viral replication, infectious virus isproduced. As expected, the genomic (viral) RNA of pestiviruses is alsoinfectious (Moennig and Plagemann, (1992) Adv. Virus Res. 41: 53-98).

In 2003 an outbreak of stillbirths and pre-weaning deaths of pigletsoccurred on two farms in New South Wales, Australia (McOrist et al,(2004) Aust Vet J. 82: 509-511). Key features of the clinicalpresentation and pathology findings suggested that this disease outbreakwas novel and probably due to a virus. Extensive testing for knownviruses and some bacteria failed to identify an aetiological agent. Toavoid confusion with other important diseases in pigs, the term “porcinemyocarditis syndrome” (abbreviated as “PMC”) was ascribed to thedisease, and the term “PMC virus” given to presumptive agent.Subsequently, the causative agent was identified as a novel pestivirus.The name Bungowannah is proposed for this new virus.

The present invention addresses a need in the art for methods ofdetecting and/or treating infections caused by the novel PMC virus.

SUMMARY OF THE INVENTION

The invention provides an isolated RNA nucleotide sequence correspondingto the PMC virus nucleotide sequence depicted in SEQ ID NO:1, orsequences substantially homologous to SEQ ID NO:1, or fragments thereof.

The invention also provides the isolated DNA nucleotide sequence of thePMC virus of SEQ ID NO:1, or sequences substantially homologous to SEQID NO:1, or fragments thereof.

The invention further provides polypeptides encoded by the above RNA andDNA nucleotide sequences and fragments thereof, and/or an isolated PMCvirus amino acid sequence as shown in SEQ ID NO: 2 and fragmentsthereof.

In another aspect, the invention provides methods for detecting thepresence of a PMC virus amino acid sequence in a sample, comprising thesteps of:

-   -   a) contacting a sample suspected of containing a PMC virus amino        acid sequence with an antibody that specifically binds to the        PMC virus amino acid sequence under conditions which allow for        the formation of reaction complexes comprising the antibody and        the PMC virus amino acid sequence; and    -   b) detecting the formation of reaction complexes comprising the        antibody and PMC virus amino acid sequence in the sample,        wherein detection of the formation of reaction complexes        indicates the presence of PMC virus amino acid sequence in the        sample.

The invention also provides methods for detecting the presence of a PMCvirus antibody in a sample, comprising the steps of:

-   -   a) contacting a sample suspected of containing a PMC virus        antibody with an amino acid sequence under conditions which        allow for the formation of reaction complexes comprising the PMC        virus antibody and the amino acid sequence; and    -   b) detecting the formation of reaction complexes comprising the        antibody and amino acid sequence in the sample, wherein        detection of the formation of reaction complexes indicates the        presence of PMC virus antibody in the sample.

Additionally, the invention provides an in vitro method for evaluatingthe level of PMC virus antibodies in a biological sample comprising thesteps of:

-   -   a) detecting the formation of reaction complexes in a biological        sample according to the method noted above; and    -   b) evaluating the amount of reaction complexes formed, which        amount of reaction complexes corresponds to the level of PMC        virus antibodies in the biological sample.

The invention also provides an in vitro method for evaluating the levelof PMC virus polypeptides in a biological sample comprising the stepsof:

-   -   a) detecting the formation of reaction complexes in a biological        sample according to the method noted above; and    -   b) evaluating the amount of reaction complexes formed, which        amount of reaction complexes corresponds to the level of PMC        virus polypeptide in the biological sample.

The present invention further provides methods for detecting thepresence or absence of PMC virus in a biological sample, which comprisethe steps of:

-   -   a) bringing the biological sample into contact with a        polynucleotide probe or primer comprising a PMC virus        polynucleotide of the invention under suitable hybridising        conditions; and    -   b) detecting any duplex formed between the probe or primer and        nucleic acid in the sample.

The present invention also relates to a method for the detection of PMCvirus nucleic acids present in a biological sample, comprising:

-   -   a) amplifying the nucleic acid with at least one primer as        defined above,    -   b) detecting the amplified nucleic acids.

The present invention also relates to a method for the detection of PMCvirus nucleic acids present in a biological sample, comprising:

-   -   a) hybridizing the nucleic acids of the biological sample at        appropriate conditions with one or more probes as defined above,    -   b) washing under appropriate conditions, and    -   c) detecting the hybrids formed.

In a further aspect, the present invention provides a method for thegeneration of antibodies comprising the steps of:

-   -   a) providing a PMC virus polypeptide sequence to a subject; and    -   b) collecting the antibodies generated in the subject against        the polypeptide.

In another aspect of the invention, there is provided a vaccinecomposition comprising a PMC virus polypeptide or fragment thereof. Theinvention also provides a vaccine composition comprising a PMC virusnucleotide or fragment thereof that encodes for a PMC virus polypeptide.

Pharmaceutical compositions comprising a PMC virus polypeptide thatenhances the immunocompetence of the host individual and elicitsspecific immunity against the PMC virus are further provided by theinvention.

The present invention also provides therapeutic compositions comprisingpolynucleotide sequences and/or antibodies prepared against thepolypeptides of the invention. The present invention further providestherapeutic compositions comprising PMC virus nucleic acid sequences aswell as antisense and ribozyme polynucleotide sequences hybridisable toa polynucleotide sequence encoding a PMC virus amino acid sequenceaccording to the invention.

The present invention provides for the use of PMC virus amino acidsequences and/or antibodies according to the invention, for manufactureof a medicament for modulation of a disease associated with PMC virus.The present invention additionally provides for the use ofpolynucleotide sequences of the invention, as well as antisense andribozyme polynucleotide sequences hybridisable to a polynucleotidesequence encoding a PMC virus amino acid sequence according to theinvention, for manufacture of a medicament for modulation of a diseaseassociated with PMC virus.

The present invention further provides a method of inducing a protectiveimmune response in an animal or human against PMC virus comprising thesteps of:

-   -   a) administering to said animal or human an effective amount of        a composition of the invention.

The present invention also provides methods for enhancing an animal'simmunocompetence and the activity of its immune effector cells against aPMC virus comprising the step of:

-   -   a) administering a composition comprising a therapeutically        effective amount of a PMC virus peptide or polypeptide.

In addition, the present invention provides a live vector comprising thePMC virus and a heterologous polynucleotide.

In another aspect of the invention, there is provided a method ofscreening for drugs comprising the steps of:

-   -   a) contacting an agent with a PMC virus amino acid sequence or        fragment thereof and    -   b) assaying for the presence of a complex between the agent and        the PMC virus amino acid sequence or fragment.

The present invention also provides a method of screening for ligands ofthe proteins of the PMC virus comprising the steps of:

-   -   a) contacting a ligand with a PMC virus amino acid sequence or        fragment thereof and    -   b) assaying for the presence of a complex between the PMC virus        amino acid sequence or fragment and a ligand.

In a further aspect of the invention, a test kit may be prepared for thedemonstration of the presence of PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled        immunochemically reactive component obtained by the direct or        indirect attachment of the present PMC virus amino acid sequence        or a specific binding partner thereto, to a detectable label;    -   (b) other reagents; and    -   (c) directions for use of said kit.

Additionally, the invention provides a test kit for the demonstration ofthe presence of PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled antibody to        the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

The invention also provides a test kit for the demonstration of thepresence of PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled polypeptide        derived from the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

Additionally the present invention provides a test kit prepared for thedemonstration of the presence of PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled nucleic acid        sequence derived from the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

The present invention also provides a recombinant expression vectorcomprising a PMC virus nucleic acid sequence or a part thereof asdefined above, operably linked to prokaryotic, eukaryotic or viraltranscription and translation control elements.

The invention further relates to the hosts (prokaryotic or eukaryoticcells) which are transformed by the above mentioned vectors andrecombinants and which are capable of expressing said RNA and/or DNAfragments.

The present invention also relates to a method for the production of arecombinant PMC virus polypeptide, comprising the steps of:

-   -   a) transforming an appropriate cellular host with a recombinant        vector, in which a PMC virus polynucleotide sequence or a part        thereof has been inserted under the control of appropriate        regulatory elements,    -   b) culturing said transformed cellular host under conditions        enabling the expression of said insert, and,    -   c) harvesting said polypeptide.

According to another embodiment the present invention provides methodsfor preparing a PMC virus amino acid sequence, comprising the steps of:

-   -   (a) culturing a cell containing a vector as described above        under conditions that provide for expression of the PMC virus        amino acid sequence; and    -   (b) recovering the expressed PMC virus sequence.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the DNA sequence (SEQ ID NO: 1) of the PMC virus of thepresent invention;

FIG. 2 shows the protein sequence (SEQ ID NO: 2) of the PMC virus of thepresent invention;

FIG. 3 shows a map of the location of primers used to sequence the wholevirus, the dotted lines underneath are the length of the PCR productsproduced and sequenced;

FIG. 4 shows an ethidium bromide stained 0.8% gel of SISPA applied toDNA and RNA of adaptor PCR (run on Corbett and Eppendorf cyclermachines). Arrows indicate where gel was cut to collect bands forpurification and cloning (e.g. ER1=Eppendorf PCR machine, RNApreparation, gel position 1). Lane 1 Eppendorf machine RNA SISPA 10 ulof PCR product; Lane 2 Eppendorf machine DNA SISPA 10 ul of PCR product;Lane 3 Eppendorf machine RNA SISPA 40 ul of PCR product; Lane 4Eppendorf machine DNA SISPA 40 ul of PCR product; Lane 5 Eppendorfmachine Blank 40 ul of PCR control; Lane 6 Corbett machine RNA SISPA 40ul of PCR product; Lane 7 Corbett machine DNA SISPA 40 ul of PCRproduct; Lane 8 Corbett machine blank 40 ul of PCR product; Lane 9 100bp marker.

FIG. 5 (A and B) show ethidium bromide stained 1% gels of SISPA appliedto DNA and RNA simultaneously to screen colonies for inserts (e.g.ER31=Eppendorf PCR machine, RNA sample position 3 colony 1). Lane 1ER31; Lane 2 ER32; Lane 3 ER33; Lane 4 ER34; Lane 5 ER35; Lane 6 ER36;Lane 7 ER37; Lane 8 ER38; Lane 9 ER39; Lane 10 ER310; Lane 11 ER311;Lane 12 ER312; Lane 13 Marker 100 bp; Lane 14 ER41; Lane 15 ER42; Lane16 ER43; Lane 17 ER44; Lane 18 ER45; Lane 19 ER46; Lane 20 ER47; Lane 21ER48; Lane 22 ER49; Lane 23 ER410; Lane 24 ER411; Lane 25 ER412; Lane 26ER51; Lane 27 ER52; Lane 28 ER53; Lane 29 ER54; Lane 30 ER55; Lane 31ER56; Lane 32 ER57; Lane 33 Marker 100 bp; Lane 34 ER58; Lane 35 ER59;Lane 36 ER5 10; Lane 37 ER511; Lane 38 ER512; Lane 39 ER61; Lane 40ER62; Lane 41 ER63; Lane 42 ER64; Lane 43 ER65; Lane 44 ER66; Lane 45ER67; Lane 46 ER68; Lane 47 ER69; Lane 48 ER610; Lane 49 ER611; Lane 50ER612; Lane 51 ER71; Lane 52 ER72; Lane 53 Marker 100 bp; Lane 54 ER73;Lane 55 ER7 4; Lane 56 ER75; Lane 57 ER76; Lane 58 ER77; Lane 59 ER78;Lane 60 ER7 10; Lane 61 ER711; Lane 62 ER712; Lane 63 ER81; Lane 64ER82; Lane 65 ER8 3; Lane 66 ER84; Lane 67 ER85; Lane 68 ER86; Lane 69ER87; Lane 70 ER8 8; Lane 71 ER89; Lane 72 ER810; Lane 73 Marker 100 bp;Lane 74 ER8 11; Lane 75 ER812; Lane 76 ER91; Lane 77 ER92; Lane 78 ER93;Lane 79 ER94; Lane 80 ER95; Lane 81 Marker 100 bp; Lane 82 ER96; Lane 83ER97; Lane 84 ER98; Lane 85 ER99; Lane 86 ER910; Lane 87 ER911; Lane 88;Lane 89 ER10 2; Lane 90 ER10 3; Lane 91 ER10 4; Lane 92 ER10 5; Lane 93ER10 6; Lane 94 ER10 7; Lane 95 ER10 8; Lane 96 ER10 9; Lane 97 ER10 10;Lane 98 ER10 11; Lane 99 ER10 12.

FIG. 6 (A and B) show ethidium bromide stained 1% gels of PCR carriedout to screen of colonies for DNA (Eppendorf cycler). Lane 1 ED21=Eppendorf machine, DNA gel cut out 2, colony 1; Lane 2 ED2 2; Lane 3ED2 3; Lane 4 ED2 4; Lane 5 ED2 5; Lane 6 ED2 6; Lane 7 ED2 7; Lane 8ED2 8; Lane 9 ED2 9; Lane 10 ED2 10; Lane 11 ED2 11; Lane 12 ED2 12;Lane 13 Marker 100 bp; Lane 14 ED3 1; Lane 15 ED3 2; Lane 16 ED3 3; Lane17 ED3 4; Lane 18 ED3 5; Lane 19 ED3 6; Lane 20 ED3 7; Lane 21 ED3 8;Lane 22 ED3 9; Lane 23 ED3 10; Lane 24 ED3 11; Lane 25 ED3 12; Lane 26ED4 1; Lane 27 ED4 2; Lane 28 ED4 3; Lane 29 ED4 4; Lane 30 ED4 5; Lane31 ED4 6; Lane 32 ED4 7; Lane 33 Marker 100 bp; Lane 34 ED4 8; Lane 35ED4 9; Lane 36 ED4 10; Lane 37 ED4 11; Lane 38 ED4 12; Lane 39 ED5 1;Lane 40 ED5 2; Lane 41 ED5 3; Lane 42 ED5 4; Lane 43 ED5 5; Lane 44 ED56; Lane 45 ED5 7; Lane 46 ED5 8; Lane 47 ED5 9; Lane 48 ED5 10; Lane 49ED5 11; Lane 50 ED5 12; Lane 51 ED6 1; Lane 52 ED6 2; Lane 53 ED6 3;Lane 54 ED6 4; Lane 55 ED6 5; Lane 56 ED6 6; Lane 57 ED6 7; Lane 58 ED68; Lane 59 ED6 9; Lane 60 Marker 100 bp; Lane 61 ED6 10; Lane 62 ED6 11;Lane 63 ED6 12; Lane 64 ED7 1; Lane 65 ED7 2; Lane 66 ED7 3; Lane 67 ED74; Lane 68 ED7 5; Lane 69 ED7 6; Lane 70 ED7 7; Lane 71 ED7 8; Lane 72ED7 9; Lane 73 ED7 10; Lane 74 ED7 11; Lane 75 ED7 12; Lane 76 ED8 1;Lane 77 ED8 2; Lane 78 ED8 3; Lane 79 ED8 4; Lane 80 ED8 5; Lane 81 ED86; Lane 82 ED8 7; Lane 83 ED8 8; Lane 84 ED8 9; Lane 85 ED8 10; Lane 86ED8 11; Lane 87 ED8 12.

FIG. 7 (A and B) show ethidium bromide stained 1% gels of PCR carriedout to screen of colonies for RNA inserts (Corbett cycler). Lane 1 CR21=Corbett machine, RNA gel position 2, colony 1; Lane 2 CR2 2; Lane 3CR2 3; Lane 4 CR2 4; Lane 5 CR2 5; Lane 6 CR2 6; Lane 7 Marker 100 bp;Lane 8 Marker 100 bp; Lane 9 CR2 7; Lane 10 CR2 8; Lane 11 CR2 9; Lane12 CR2 10; Lane 13 CR2 11; Lane 14 CR2 12; Lane 15 CR3 1; Lane 16 CR3 2;Lane 17 CR3 3; Lane 18 CR3 4; Lane 19 CR3 5; Lane 20 CR3 6; Lane 21 CR37; Lane 22 CR3 8; Lane 23 CR3 9; Lane 24 CR3 10; Lane 25 CR3 11; Lane 26CR3 12; Lane 27 Marker 100 bp; Lane 28 Marker 100 bp; Lane 29 CR4 1;Lane 30 CR4 2; Lane 31 CR4 3; Lane 32 CR4 4; Lane 33 CR4 5; Lane 34 CR46; Lane 35 CR4 7; Lane 36 CR4 8; Lane 37; CR4 9; Lane 38 CR4 10; Lane 39CR4 11; Lane 40 CR4 12; Lane 41 marker 100 bp; Lane 42 marker 100 bp;Lane 43 CR5 1; Lane 44 CR5 2; Lane 45 CR5 3; Lane 46 CR5 4; Lane 47 CR55; Lane 48 CR5 6; Lane 49 CR5 7; Lane 50 CR5 8; Lane 51 CR5 9; Lane 52CR5 10; Lane 53 CR5 11; Lane 54 PCR Blank control; Lane 55 marker 100bp.

FIG. 8 (A and B) show ethidium bromide stained 1% gels of PCR carriedout to screen colonies for DNA (Corbett cycler). Lane 1 marker 100 bp;Lane 2 CD3 1=Corbett machine, DNA gel cut out 3, colony 1; Lane 3 CD3 2;Lane 4 CD3 3; Lane 5 CD3 4; Lane 6 CD3 5; Lane 7 CD3 6; Lane 8 CD3 7;Lane 9 CD3 8; Lane 10 CD3 9; Lane 11 CD3 10; Lane 12 CD3 11; Lane 13 CD312; Lane 14 CD4 1; Lane 15 CD4 2; Lane 16 CD4 3; Lane 17 CD4 4; Lane 18CD4 5; Lane 19 CD4 6; Lane 20 marker 100 bp; Lane 21 marker 100 bp; Lane22 CD4 7; Lane 23 CD4 8; Lane 24 CD4 9; Lane 25 CD4 10; Lane 26 CD4 11;Lane 27 CD4 12; Lane 28 CD5 1; Lane 29 CD5 2; Lane 30 CD5 3; Lane 31 CD54; Lane 32 CD5 5; Lane 33 CD5 6; Lane 34 CD5 7; Lane 35 CD5 8; Lane 36CD5 9; Lane 37 CD5 10; Lane 38 CD5 11; Lane 39 CD5 12; Lane 40 marker100 bp; Lane 41 marker 100 bp; Lane 42 CD6 1; Lane 43 CD6 2; Lane 44 CD63; Lane 45 CD6 4; Lane 46 CD6 5; Lane 47 CD6 6; Lane 48 CD6 7; Lane 49CD6 8; Lane 50 CD6 9; Lane 51 CD6 10; Lane 52 CD6 11; Lane 53 CD6 12.

FIG. 9 shows an ethidium bromide stained 1.5% gel of PCR carried out toconfirm authenticity of viral sequence for virus confirmation bynRT-PCR. PCR results confirmed the presence of Pestivirus in clinicalspecimens (lanes 3, 8 and 23) while EMCV was not present (lane 28)(lanes marked + are PCR positive). Lane 1 Marker 100 bp; Lane 2 BlankCR39 primers; Lane 3 SISPA sera CR39 primers; Lane 4 NADL +ve controlCR39 primers; Lane 5 EMCV −ve control CR39 primers; Lane 6; Lane 7 BlankER510 primers; Lane 8 SISPA sera ER510 primers; Lane 9 NADL +ve controlER510 primers; Lane 10 EMCV −ve control ER510 primers; Lane 11; Lane 12Blank ER55 primers; Lane 13 SISPA sera ER55 primers; Lane 14 NADL +vecontrol ER55 primers; Lane 15 EMCV −ve control ER55 primers; Lane 16;Lane 17; Lane 18; Lane 19; Lane 20 Marker 100 bp; Lane 21 Marker 100 bp;Lane 22 Blank ER62 primers; Lane 23 SISPA sera ER62 primers; Lane 24NADL +ve control ER62 primers; Lane 25 EMCV −ve control ER62 primers;Lane 26; Lane 27 Blank ER41 primers; Lane 28 SISPA sera ER41 primers;Lane 29 NADL +ve control ER41 primers; Lane 30 EMCV −ve control ER41primers; Lane 31; Lane 32; Lane 33; Lane 34; Lane 35; Lane 36; Lane 37;Lane 38; Lane 39; Lane 40 marker 100 bp.

FIG. 10 shows a hydrophobicity plot of the PMC virus protein sequence.

DETAILED DESCRIPTION OF THE INVENTION

New Pestivirus

In accordance with this invention, a new pestivirus has been discoveredthat differs genetically from known pestiviruses. The new virus ischaracterised by the RNA sequence corresponding to that shown in SEQ IDNO: 1. The sequence has been deposited as Genbank reference EF100713.

The new virus is hereinafter generally referred to as PMC virus and thecondition caused by infection with the PMC virus is PMC.

The PMC virus genome comprises a single open reading frame (ORF),encoding a number of genes. The genes encoded by the ORF of PMCcorrespond to those of other pestiviruses, being the Npro, capsid, E0,E1, E2, P7, NS2, NS3, NS4A, NS4B, NS5A and NS5B genes.

The PMC virus is approximately 40% similar to other pestiviruses on anucleic acid sequence level. At the protein level, PMC virus has 46-71%identity and 63-83% similarity with other pestiviruses. A comparativeanalysis of both the nucleic acid and deduced amino acid sequences wouldsuggest that PMC virus is sufficiently unique to warrant considerationfor classification as a new species within the pestivirus genus.

Open Reading Frames, Encoded Genes, Features of RNA Genomes

The nucleotide sequence of SEQ ID NO:1 encodes a single ORF encoding anumber of different genes. The genes encoded by SEQ ID NO:1 correspondto the Npro, capsid, E0, E1, E2, P7, NS2, NS3, NS4A, NS4B, NS5A and NS5Bgenes of other pestiviruses.

The approximate location of the genes of PMC, based on sequencecomparison with gi12657941, is indicated in Table 1.

TABLE 1 Location of proteins within PMC nucleic acid open-reading frame.PROTEIN APPROXIMATE DNA POSITION NPro 419-922 Capsid  923-1219 E01220-1885 E1 1886-2473 E2 2474-3604 P7 3605-3820 NS2 3821-5224 NS35225-7252 NS4A 7253-7441 NS4B 7442-8482 NS5A 8483-9997 NS5B  9998-12077

TABLE 2 Location of proteins within PMC protein open-reading frame.APPROXIMATE AMINO PROTEIN ACID POSITION NPro  1-167 Capsid 168-267 E0268-489 E1 490-685 E2  686-1062 P7 1063-1134 NS2 1135-1602 NS3 1603-2278NS4A 2279-2341 NS4B 2342-2688 NS5A 2689-3193 NS5B 3194-3886Nucleic Acid SequencesRNA

The invention provides an isolated RNA nucleotide sequence correspondingto the PMC virus nucleotide sequence depicted in SEQ ID NO:1, orsequences substantially homologous to SEQ ID NO:1, or fragments thereof.The invention further provides an RNA sequence comprising the complementof the PMC virus RNA genome, or fragments thereof.

The RNA sequence may also correspond to a fragment of SEQ ID NO:1.Preferably, the fragment is selected from the following locations of SEQID NO:1: position 419-922, 923-1219, 1220-1885, 1886-2473, 2474-3604,3605-3820, 3821-5224, 5225-7252, 7253-7441, 7442-8482, 8483-9997,9998-12077. Alternatively, the fragment may be selected from any one ofSEQ ID NOs:3-15.

Substantial homology or identity exists when a PMC virus polynucleotidesequence or fragment thereof will hybridise to another PMC viruspolynucleotide (or a complementary strand thereof) under selectivehybridisation conditions.

Selective hybridisation may be under low, moderate or high stringencyconditions, but is preferably under high stringency.

Typically, selective hybridisation will occur when there is at leastabout 55% identity over a stretch of at least about 14 nucleotides,preferably at least about 65%, more preferably at least about 75% andmost preferably at least about 90%. The length of homology comparison,as described, may be over longer stretches and in certain embodimentswill often be over a stretch of at least about nine nucleotides, usuallyat least about 20 nucleotides, more usually at least about 24nucleotides, typically at least about 28 nucleotides, more typically atleast about 32 nucleotides and preferably at least about 36 or morenucleotides.

Thus, the polynucleotide sequences of the invention preferably have atleast 75%, more preferably at least 85%, more preferably at least 90%homology to the sequences shown in the sequence listings herein. Morepreferably there is at least 95%, more preferably at least 98%,homology. Nucleotide homology comparisons may be conducted as describedbelow for polypeptides. A preferred sequence comparison program is theGCG Wisconsin Bestfit program.

In the context of the present invention, a homologous sequence is takento include a nucleotide sequence which is at least 60, 70, 80 or 90%identical, preferably at least 95 or 98% identical at the nucleic acidlevel over at least 20, 50, 100, 200, 300, 500 or 819 nucleotides withthe corresponding nucleotide sequences set out in SEQ ID NO:1. Inparticular, homology should typically be considered with respect tothose regions of the sequence that encode contiguous amino acidsequences known to be essential for the function of one or more of PMCvirus proteins, rather than non-essential neighbouring sequences.

PMC virus polynucleotide sequence fragments of the invention willpreferably be at least 15 nucleotides in length, more preferably atleast 20, 30, 40, 50, 100 or 200 nucleotides in length. Generally, theshorter the length of the polynucleotide sequence, the greater thehomology required to obtain selective hybridisation. Consequently, wherea polynucleotide sequence of the invention consists of less than about30 nucleotides, it is preferred that the percentage identity is greaterthan 75%, preferably greater than 90% or 95% compared with thepolynucleotide sequences set out in the sequence listings herein.Conversely, where a polynucleotide sequence of the invention consistsof, for example, greater than 50 or 100 nucleotides, the percentageidentity compared with the polynucleotide sequences set out in thesequence listings herein may be lower, for example greater than 50%,preferably greater than 60 or 75%.

Nucleic acid sequences according to the present invention which arehomologous to the sequences as represented by a SEQ ID NO: 1 can becharacterized and isolated according to any of the techniques known inthe art, such as amplification by means of sequence-specific primers,hybridization with sequence-specific probes under more or less stringentconditions, serological screening methods or via the LiPA typing system.

DNA

The DNA of the new PMC virus also is provided. The DNA sequence ispreferably derived from the RNA sequences described above. Mostpreferably, the DNA sequence is that shown in SEQ ID NO: 1 or fragmentsthereof.

The invention also provides DNA fragments hybridisable with the genomicRNA of PMC. The DNA or DNA fragment sequence may be derived from thecDNA sequence of the PMC virus or fragments thereof. The DNA, cDNA orfragments thereof may be in the form of recombinant DNAs.

The DNA sequence may also be a fragment of SEQ ID NO:1. Preferably, thefragment is selected from the following locations of SEQ ID NO:1:position 419-922, 923-1219, 1220-1885, 1886-2473, 2474-3604, 3605-3820,3821-5224, 5225-7252, 7253-7441, 7442-8482, 8483-9997, 9998-12077.

Variant Nucleic Acids

Nucleic acid sequences and fragments, which would include some deletionsor mutations which would not substantially alter their ability tohybridizing with the genome of PMC virus, are also provided by thepresent invention. Such variants are to be considered as forming obviousequivalents of the RNA, DNA or fragments referred to above.

Other preferred variant nucleic acid sequences of the present inventioninclude sequences which are redundant as a result of the degeneracy ofthe genetic code compared to any of the above-given nucleic acidsequences of the present invention. These variant nucleic acid sequenceswill thus encode the same amino acid sequences as the nucleic acidsequences they are derived from. Preferably, the RNAs of these variants,and the related cDNAs derived from said RNAs, are hybridisable tocorresponding parts of the RNA and cDNA of PMC virus.

Also included within the present invention are sequence variants of theDNA sequence of SEQ ID NO: 1 or corresponding RNA sequence or fragmentsthereof, containing either deletions and/or insertions of one or morenucleotides, especially insertions or deletions of 1 or more codons.

Also included are substitutions of some non-essential nucleotides byothers (including modified nucleotides and/or inosine).

Particularly preferred variant polynucleotides of the present inventionalso include sequences which hybridise under stringent conditions withany of the nucleic acid sequences of the present invention. Thus,sequences which show a high degree of homology (similarity) to any ofthe nucleic acid sequences of the invention as described above arepreferred. Particularly preferred are sequences which are at least 80%,85%, 90%, 95% or more homologous to said nucleic acid sequences of theinvention. Preferably, said sequences will have less than 20%, 15%, 10%,or 5% variation of the original nucleotides of said nucleic acidsequences.

Probes and Primers

Primer and probes are further provided, which can be made starting fromany RNA or DNA sequence or sequence fragment according to the invention.Preferably, such probes or primers are between about 5 to 50 nucleotideslong, more preferably from about 10 to 25 nucleotides. Probes andprimers of the present invention may be used in PCR, sequencingreactions, hybridisation reactions and other applications known to theskilled person.

The present invention also relates to an oligonucleotide primercomprising part of SEQ ID NO: 1, said primer being able to act as aprimer for specifically amplifying the nucleic acid of the PMC virus.Preferably, the primer is a single stranded DNA oligonucleotide sequencecapable of acting as a point of initiation for synthesis of a primerextension product which is complementary to the nucleic acid strand tobe copied. The specific length and sequence of the primer used willdepend on the complexity of the required DNA or RNA targets, as well ason the conditions of primer use, such as temperature and ionic strength.The fact that amplification primers do not have to match exactly withcorresponding template sequence to warrant proper amplification is amplydocumented in the literature (Kwok et al., 1990).

The amplification method used can be either polymerase chain reaction(PCR; Saiki et al., 1988), ligase chain reaction (LCR; Landgren et al.,1988; Wu & Wallace, 1989; Barany, 1991), nucleic acid sequence-basedamplification (NASBA; Guatelli et al., 1990; Compton, 1991),transcription-based amplification system (TAS; Kwoh et al., 1989),strand displacement amplification (SDA; Duck, 1990; Walker et al., 1992)or amplification by means of Qβ replicase (Lizardi et al., 1988; Lomeliet al., 1989) or any other suitable method to amplify nucleic acidmolecules using primer extension. During amplification, the amplifiedproducts can be conveniently labelled either using labelled primers orby incorporating labelled nucleotides. Labels may be isotopic (³²P, ³⁵S,etc.) or non-isotopic (biotin, digoxigenin, etc.). The amplificationreaction is repeated between 20 and 70 times, advantageously between 25and 45 times.

The present invention also relates to an oligonucleotide probecomprising part of SEQ ID NO:1, with said probe being able to act as ahybridisation probe for the PMC virus. Preferably, the probe can be usedfor specific detection and/or classification into types and/or subtypesof PMC virus. Preferably, the probe is a single strandedsequence-specific oligonucleotide sequence which has a sequence that iscomplementary to the target sequence of the PMC virus to be detected.

Those skilled in the art will recognise that the stringency ofhybridisation will be affected by such conditions as salt concentration,temperature, or organic solvents, in addition to the base composition,length of the complementary strands and the number of nucleotide basemismatches between the hybridising nucleic acids. Stringent temperatureconditions will generally include temperatures in excess of 30° C.,typically in excess of 37° C., and preferably in excess of 45° C.Stringent salt conditions will ordinarily be less than 1000 mM,typically less than 500 mM, and preferably less than 200 mM. However,the combination of parameters is much more important than the measure ofany single parameter. An example of stringent hybridisation conditionsis 65° C. and 0.1×SSC (1×SSC=0.15 M NaCl, 0.015 M sodium citrate pH7.0).

Optionally, the probe of the invention is labelled and/or attached to asolid substrate. The solid substrate can refer to any substrate to whichan oligonucleotide probe can be coupled, provided that it retains itshybridization characteristics and provided that the background level ofhybridization remains low. Usually the solid substrate will be amicrotiter plate, a membrane (e.g. nylon or nitrocellulose) or amicrosphere (bead). Prior to application to the membrane or fixation itmay be convenient to modify the nucleic acid probe in order tofacilitate fixation or improve the hybridization efficiency. Suchmodifications may encompass homopolymer tailing, coupling with differentreactive groups such as aliphatic groups, NH₂ groups, SH groups,carboxylic groups, or coupling with biotin or haptens.

The probes of the invention may include also an isolated polynucleotideattached to a label or reporter molecule and may be used to isolateother polynucleotide sequences, having sequence similarity by standardmethods. For techniques for preparing and labelling probes see, e.g.Sambrook et al., (1989) or Ausubel et al., (2001).

Oligonucleotides according to the present invention and used as primersor probes may also contain or consist of nucleotide analogues such asphosphorothioates (Matsukura et al., 1987), alkylphosphoriates (Milleret al., 1979) or peptide nucleic acids (Nielsen et al., 1991; Nielsen etal., 1993) or may contain interculating agents (Asseline et al., 1984).The introduction of these modifications may be advantageous in order topositively influence characteristics such as hybridization kinetics,reversibility of the hybrid-formation, biological stability of theoligonucleotide molecules, etc.

Recombinant DNAs containing fragments of the DNA sequence of PMC virusare also provided by the present invention, and may be used as, forexample, probes. Preferably, the plasmid used to generate therecombinant DNA is a plasmid amplifiable in prokaryotic or eukaryoticcells and carrying said fragments. For example, using cloned DNAcontaining a DNA fragment of PMC virus as a molecular hybridizationprobe, either by marking with radionucleotides or with fluorescentreagents, PMC virus RNA may be detected directly, for example, in blood,body fluids and blood products.

Nucleic Acid Arrays

PMC virus polynucleotide sequences (preferably in the form of probes)may also be immobilised to a solid phase support for the detection ofPMC virus. Alternatively the PMC virus polynucleotide sequences willform part of a library of DNA molecules that may be used to detectsimultaneously a number of different genes from PMC virus. In a furtheralternate form of the invention, PMC virus polynucleotide sequencestogether with other polynucleotide sequences (such as from otherbacteria or viruses) may be immobilised on a solid support in such amanner permitting identification of the presence of PMC virus and/or anyof the other polynucleotide sequences bound onto the solid support.

Techniques for producing immobilised libraries of DNA molecules havebeen described in the art. Generally, most prior art methods describethe synthesis of single-stranded nucleic acid molecule libraries, usingfor example masking techniques to build up various permutations ofsequences at the various discrete positions on the solid substrate. U.S.Pat. No. 5,837,832 describes an improved method for producing DNA arraysimmobilised to silicon substrates based on very large scale integrationtechnology. In particular, U.S. Pat. No. 5,837,832 describes a strategycalled “tiling” to synthesize specific sets of probes at spatiallydefined locations on a substrate that may be used to produce theimmobilised DNA libraries of the present invention. U.S. Pat. No.5,837,832 also provides references for earlier techniques that may alsobe used. Thus polynucleotide sequence probes may be synthesised in situon the surface of the substrate.

Alternatively, single-stranded molecules may be synthesised off thesolid substrate and each pre-formed sequence applied to a discreteposition on the solid substrate. For example, polynucleotide sequencesmay be printed directly onto the substrate using robotic devicesequipped with either pins or pizo electric devices.

The library sequences are typically immobilised onto or in discreteregions of a solid substrate. The substrate may be porous to allowimmobilisation within the substrate or substantially non-porous, inwhich case the library sequences are typically immobilised on thesurface of the substrate. The solid substrate may be made of anymaterial to which polypeptides can bind, either directly or indirectly.Examples of suitable solid substrates include flat glass, siliconwafers, mica, ceramics and organic polymers such as plastics, includingpolystyrene and polymethacrylate. It may also be possible to usesemi-permeable membranes such as nitrocellulose or nylon membranes,which are widely available. The semi-permeable membranes may be mountedon a more robust solid surface such as glass. The surfaces mayoptionally be coated with a layer of metal, such as gold, platinum orother transition metal. A particular example of a suitable solidsubstrate is the commercially available BiaCore™ chip (PharmaciaBiosensors).

Preferably, the solid substrate is generally a material having a rigidor semi-rigid surface. In preferred embodiments, at least one surface ofthe substrate will be substantially flat, although in some embodimentsit may be desirable to physically separate regions for differentpolymers with, for example, raised regions or etched trenches. It isalso preferred that the solid substrate is suitable for the high densityapplication of DNA sequences in discrete areas of typically from 50 to100 μm, giving a density of 10000 to 40000 dots/cm⁻².

The solid substrate is conveniently divided up into sections. This maybe achieved by techniques such as photoetching, or by the application ofhydrophobic inks, for example teflon-based inks (Cel-line, USA).

Discrete positions, in which each different member of the library islocated may have any convenient shape, e.g., circular, rectangular,elliptical, wedge-shaped, etc.

Attachment of the polynucleotide sequences to the substrate may be bycovalent or non-covalent means. The polynucleotide sequences may beattached to the substrate via a layer of molecules to which the librarysequences bind. For example, the polynucleotide sequences may belabelled with biotin and the substrate coated with avidin and/orstreptavidin. A convenient feature of using biotinylated polynucleotidesequences is that the efficiency of coupling to the solid substrate canbe determined easily. Since the polynucleotide sequences may bind onlypoorly to some solid substrates, it is often necessary to provide achemical interface between the solid substrate (such as in the case ofglass) and the nucleic acid sequences. Examples of suitable chemicalinterfaces include hexaethylene glycol. Another example is the use ofpolylysine coated glass, the polylysine then being chemically modifiedusing standard procedures to introduce an affinity ligand. Other methodsfor attaching molecules to the surfaces of solid substrate by the use ofcoupling agents are known in the art, see for example WO98/49557.

Binding of complementary polynucleotide sequences to the immobilisednucleic acid library may be determined by a variety of means such aschanges in the optical characteristics of the bound polynucleotidesequence (i.e. by the use of ethidium bromide) or by the use of labellednucleic acids, such as polypeptides labelled with fluorophores. Otherdetection techniques that do not require the use of labels includeoptical techniques such as optoacoustics, reflectometry, ellipsometryand surface plasmon resonance (see WO97/49989).

Thus, the present invention provides a solid substrate havingimmobilized thereon at least one polynucleotide of the presentinvention, preferably two or more different polynucleotide sequences ofthe present invention. In a preferred embodiment the solid substratefurther comprises polynucleotide sequences derived from genes other thanthe PMC virus polynucleotide sequence.

Antisense Nucleic Acids and Ribozymes

The present invention also extends to the preparation of antisensenucleotides and ribozymes that may be used to interfere with theexpression of PMC virus amino acid sequences at the translational level.This approach utilises antisense nucleic acid and ribozymes to blocktranslation of a specific mRNA, either by masking that mRNA with anantisense nucleic acid or cleaving it with a ribozyme.

Antisense nucleic acids are DNA or RNA molecules that are complementaryto at least a portion of a specific mRNA molecule [See: Weintraub,(1990) Sci. Am., 262:40-46; Marcus-Sekura, (1988) Anal. Biochem.,172:289-295]. In the cell, they hybridise to that mRNA, forming adouble-stranded molecule. The cell does not translate an mRNA complexedin this double-stranded form. Therefore, antisense nucleic acidsinterfere with the expression of mRNA into protein. Oligomers of aboutfifteen nucleotides and molecules that hybridise to the AUG initiationcodon will be particularly efficient, since they are easy to synthesizeand are likely to pose fewer problems than larger molecules whenintroducing them into infected cells. Antisense methods have been usedto inhibit the expression of many genes in vitro [Hambor et al., (1988)J. Exp. Med., 168:1237-1245].

Ribozymes are RNA molecules possessing the ability to specificallycleave other single-stranded RNA molecules in a manner somewhatanalogous to DNA restriction endonucleases. Ribozymes were discoveredfrom the observation that certain mRNAs have the ability to excise theirown introns. By modifying the nucleotide sequence of these RNAs,researchers have been able to engineer molecules that recognise specificnucleotide sequences in an RNA molecule and cleave it [Cech, (1988) J.Am. Med. Assoc., 260:3030-3034]. Because they are sequence-specific,only mRNAs with particular sequences are inactivated.

Investigators have identified two types of ribozymes, Tetrahymena-typeand “hammerhead”-type. Tetrahymena-type ribozymes recognize four-basesequences, while “hammerhead”-type recognize eleven- to eighteen-basesequences. The longer the recognition sequence, the more likely it is tooccur exclusively in the target mRNA species. Therefore, hammerhead-typeribozymes are preferable to Tetrahymena-type ribozymes for inactivatinga specific mRNA species and eighteen base recognition sequences arepreferable to shorter recognition sequences.

The PMC polynucleotide sequences described herein may thus be used toprepare antisense molecules against, and ribozymes that cleave, mRNAsfor PMC virus amino acid sequences, thus inhibiting expression of thePMC virus polynucleotide sequences.

Polypeptide Sequences

Polypeptides

The invention also covers polypeptides encoded by the above RNA and DNAnucleotide sequences and fragments thereof. The invention furtherprovides an isolated PMC virus amino acid sequence as shown in SEQ IDNO: 2 and fragments thereof. More desirably, the PMC virus amino acidsequence is provided in substantially purified form. Further providedare polypeptide fragments having lower molecular weights and havingpeptide sequences or fragments in common with those shown in SEQ IDNO:2.

The term “isolated” is used to describe a PMC virus amino acid sequencethat has been separated from components that accompany it in its naturalstate. Further, a PMC virus amino acid sequence is “substantiallypurified” when at least about 60 to 75% of a sample exhibits a singlePMC virus amino acid sequence. A substantially purified PMC virus aminoacid sequence will typically comprise about 60 to 90% W/W of a PMC virusamino acid sequence sample, more usually about 95%, and preferably willbe over about 99% pure. Protein purity or homogeneity may be indicatedby a number of means well known in the art, such as polyacrylamide gelelectrophoresis of a protein sample, followed by visualizing a singlePMC virus amino acid sequence band upon staining the gel. For certainpurposes, higher resolution may be provided by using HPLC or other meanswell known in the art which are utilised for application.

The invention further contemplates fragments of the PMC virus amino acidsequence. A PMC virus amino acid sequence fragment is a stretch of aminoacid residues of at least about five to seven contiguous amino acids,often at least about seven to nine contiguous amino acids, typically atleast about nine to 13 contiguous amino acids and, most preferably, atleast about 20 to 30 or more contiguous amino acids.

In a highly preferred form of the invention the fragments exhibitligand-binding, immunological activity and/or other biologicalactivities characteristic of PMC virus amino acid sequences. Morepreferably, the fragments possess immunological epitopes consistent withthose present on native PMC virus amino acid sequences.

As used herein, “epitope” refers to an antigenic determinant of apolypeptide. An epitope could comprise three amino acids in a spatialconformation that is unique to the epitope. Generally, an epitopeconsists of at least five amino acids, and more usually consists of atleast 8-10 amino acids. Methods of determining the spatial conformationof such amino acids are known in the art.

Preferred PMC virus amino acid sequences of the invention will have oneor more biological properties (eg in vivo, in vitro or immunologicalproperties) of the native full-length PMC virus amino acid sequence.Alternatively, fragments of the full-length PMC virus amino acidsequence may have one or more biological properties of one or more ofthe genes which the full length amino acid sequence encodes.

Preferably, the fragments of the full length PMC virus amino acidsequence SEQ ID NO:2 are chosen from the following locations in SEQ IDNO:2: 1-167, 168-267, 268-489, 490-685, 686-1062, 1063-1134, 1135-1602,1603-2278, 2279-2341, 2342-2688, 2689-3193, 3194-3886. Alternatively,the fragment may be selected from any one of SEQ ID NOs:16-27.

Non-functional PMC virus amino acid sequences are also included withinthe scope of the invention since they may be useful, for example, asantagonists of PMC virus genes. The biological properties of analogues,fragments, or derivatives relative to wild type may be determined, forexample, by means of biological assays.

PMC virus amino acid sequences, including analogues, fragments andderivatives, can be prepared synthetically (e.g., using the well knowntechniques of solid phase or solution phase peptide synthesis).Preferably, solid phase synthetic techniques are employed.Alternatively, PMC virus amino acid sequences of the invention can beprepared using well known genetic engineering techniques, as describedinfra. In yet another embodiment, PMC virus amino acid sequences can bepurified (e.g., by immunoaffinity purification) from a biological fluid,such as but not limited to whole blood, plasma, faeces, serum, or urinefrom animals, including pigs, cattle, sheep, chickens, human beings,dogs, horses, and fish.

Variant Polypeptides

PMC virus amino acid sequence analogues preferably include those havingan amino acid sequence wherein one or more of the amino acids issubstituted with another amino acid, which substitutions do notsubstantially alter the biological activity of the molecule.

In the context of the invention, an analogous sequence is taken toinclude a PMC virus amino acid sequence which is at least 60, 70, 80 or90% homologous, preferably at least 95 or 98% homologous at the aminoacid level over at least 20, 50, 100 or 200 amino acids, with the aminoacid sequence set out in SEQ ID NO:1. In particular, homology shouldtypically be considered with respect to those regions of the sequenceknown to be essential for the function of the protein or proteinsencoded by the PMC virus RNA, rather than non-essential neighbouringsequences.

Although homology can be considered in terms of similarity (i.e. aminoacid residues having similar chemical properties/functions), in thecontext of the present invention it is preferred to express homology interms of sequence identity. The terms “substantial homology” or“substantial identity”, when referring to PMC virus amino acidsequences, indicate that the PMC virus amino acid sequence in questionexhibits at least about 70% identity with an entire naturally-occurringPMC amino acid sequence or portion thereof, usually at least about 80%identity and preferably at least about 90 or 95% identity.

In a highly preferred form of the invention, a PMC virus amino acidsequence analogue will have 80% or greater amino acid sequence identityto the PMC virus amino acid sequence set out in SEQ ID NO:2. Examples ofPMC virus amino acid sequence analogues within the scope of theinvention include the amino acid sequence of SEQ ID NO:2 wherein: (a)one or more aspartic acid residues is substituted with glutamic acid;(b) one or more isoleucine residues is substituted with leucine; (c) oneor more glycine or valine residues is substituted with alanine; (d) oneor more arginine residues is substituted with histidine; or (e) one ormore tyrosine or phenylalanine residues is substituted with tryptophan.

PMC virus amino acid sequence derivatives are also provided by theinvention and include PMC virus amino acid sequences, analogues orfragments thereof which are substantially homologous in primarystructure but which include chemical and/or biochemical modifications orunusual amino acids. Such modifications include, for example,acetylation, carboxylation, phosphorylation, glycosylation,ubiquitination, labelling, (e.g., with radionucleotides), and variousenzymatic modifications, as will be readily appreciated by those wellskilled in the art.

In one form of the invention the chemical moieties suitable forderivatisation are selected from among water soluble polymers. Thepolymer selected should be water soluble so that the protein to which itis attached does not precipitate in an aqueous environment, such as aphysiological environment. Preferably, for therapeutic use of theend-product preparation, the polymer will be pharmaceuticallyacceptable. One skilled in the art will be able to select the desiredpolymer based on considerations such as whether the polymer/proteinconjugate will be used therapeutically, and if so, the desired dosage,circulation time, resistance to proteolysis and other considerations.For the present proteins and peptides, these may be ascertained usingthe assays provided herein.

The water soluble polymer may be selected from the group consisting of,for example, polyethylene glycol, copolymers of ethyleneglycol/propylene glycol, carboxymethylcellulose, dextran, polyvinylalcohol, polyvinyl pyrrolidone, poly-1,3-dioxolane, poly-1,3,6-trioxane,ethylene/maleic anhydride copolymer, polyaminoacids (either homopolymersor random copolymers), and dextran or poly(n-vinylpyrrolidone)polyethylene glycol, propropylene glycol homopolymers,polypropylene oxide/ethylene oxide co-polymers, polyoxyethylated polyolsand polyvinyl alcohol. Polyethylene glycol propionaldehyde may provideadvantages in manufacturing due to its stability in water.

In another form of the invention the amino acid sequences may bemodified to produce a longer half life in an animal host, for example,by fusing one or more antibody fragments (such as an Fc fragment) to theamino or carboxyl end of a PMC virus amino acid sequence.

Where the PMC virus amino acid sequence is to be provided in a labelledform, a variety of methods for labelling amino acid sequences are wellknown in the art and include radioactive isotopes such as ³²P, ligandswhich bind to labelled antiligands (eg, antibodies), fluorophores,chemiluminescent agents, enzymes and antiligands which can serve asspecific binding pair members for a labelled ligand. The choice of labeldepends on the sensitivity required, stability requirements, andavailable instrumentation. Methods of labelling amino acid sequences arewell known in the art [See, e.g., Sambrook at al., Molecular Cloning: ALaboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y. (1989); and Ausubel, F., Brent, R., Kingston,R. E., Moore, D. D., Seidman, J. G., Smith, J. A., Struhl, K. Currentprotocols in molecular biology. Greene Publishing Associates/WileyIntersciences, New York (2001)].

The PMC virus amino acid sequences of the invention, if soluble, may becoupled to a solid-phase support, e.g., nitrocellulose, nylon, columnpacking materials (e.g., Sepharose beads), magnetic beads, glass wool,plastic, metal, polymer gels, cells, or other substrates. Such supportsmay take the form, for example, of beads, wells, dipsticks, ormembranes.

The invention also provides for fusion polypeptides, comprising PMCvirus amino acid sequences and fragments. Thus PMC virus amino acidsequences may be fusions between two or more PMC virus amino acidsequences or between a PMC virus amino acid sequence and a relatedprotein. Likewise, heterologous fusions may be constructed which wouldexhibit a combination of properties or activities of the derivativeproteins. For example, ligand-binding or other domains may be “swapped”between different fusion polypeptides or fragments. Such homologous orheterologous fusion polypeptides may display, for example, alteredstrength or specificity of binding. Fusion partners includeimmunoglobulins, bacterial beta-galactosidase, trpE, protein A,beta-lactamase, alpha amylase, alcohol dehydrogenase and yeast alphamating factor.

Modified PMC virus amino acid sequences may be synthesised usingconventional techniques, or may be encoded by a modified polynucleotidesequence and produced using recombinant nucleic acid methods. Themodified polynucleotide sequence may also be prepared by conventionaltechniques. Fusion proteins will typically be made by either recombinantnucleic acid methods or may be chemically synthesised.

Diagnostics

In accordance with another embodiment the invention provides diagnosticand prognostic methods to detect the presence of PMC virus using PMCvirus glycoproteins, proteins and other peptides and polypeptides(whether obtained in a purified state from PMC virus preparations, or bychemical synthesis) and/or antibodies derived there from and/or PMCvirus polynucleotide sequences.

Diagnostic and prognostic methods will generally be conducted using abiological sample obtained from an animal, such as a pig. A “sample”refers to a sample of tissue or fluid suspected of containing a PMCpolynucleotide or polypeptide from an animal, but not limited to, e.g.,whole blood, blood cells, plasma, serum, milk, faecal samples, tissueand samples of in vitro cell culture constituents.

Polypeptide/Antibody-Based Diagnostics

Means are provided for the detection of proteins of PMC virus,particularly for the diagnosis of PMC or for the detection of antibodiesagainst PMC virus or its proteins, particularly in subjects afflictedwith PMC or more generally in asymtomatic carriers and in animal derivedproducts such as meat. Such methods are also referred to asimmunoassays.

The invention thus provides a method for detecting the presence of a PMCvirus amino acid sequence in a sample, comprising the steps of:

-   -   a) contacting a sample suspected of containing a PMC virus amino        acid sequence with an antibody that specifically binds to the        PMC virus amino acid sequence under conditions which allow for        the formation of reaction complexes comprising the antibody and        the PMC virus amino acid sequence; and    -   b) detecting the formation of reaction complexes comprising the        antibody and PMC virus amino acid sequence in the sample,        wherein detection of the formation of reaction complexes        indicates the presence of PMC virus amino acid sequence in the        sample.

Particularly the invention relates to an in vitro process of diagnosismaking use of an amino acid sequence encoding an envelope glycoproteinor of a polypeptide bearing an epitope of a glycoprotein from PMC virusor any other viral protein (structural or non-structural) for thedetection of anti-PMC virus antibodies in serum, milk or body fluids.Preferably, the antibody used in the above methods binds to the E0, E1,E2, NS2, NS3, NS4A, NS4B and/or NS5A, NS5B proteins of PMC virus.

The invention also provides a method for detecting the presence of a PMCvirus antibody in a sample, comprising the steps of:

-   -   a) contacting a sample suspected of containing a PMC virus        antibody with an amino acid sequence under conditions which        allow for the formation of reaction complexes comprising the PMC        virus antibody and the amino acid sequence; and    -   b) detecting the formation of reaction complexes comprising the        antibody and amino acid sequence in the sample, wherein        detection of the formation of reaction complexes indicates the        presence of PMC virus antibody in the sample.

A method is also provided for the detection of anti-PMC virusantibodies, comprising the steps of:

-   -   a) depositing a predetermined amount of one or several PMC virus        antigens onto a solid support such as a microplate;    -   b) introducing increasing dilutions of a biological fluid (e.g.,        blood serum or plasma, milk, cerebrospinal fluid, lymphatic        fluid or other body fluids) onto the antigens and incubating;    -   c) washing the solid support with an appropriate buffer;    -   d) adding specific labelled antibodies directed against the        antibodies of the subject; and    -   e) detecting the antigen-antibody-antibody complex formed, which        is then indicative of the presence of PMC virus antibodies in        the biological fluid.

Preferably, the antibody used in these methods is derived from anaffinity-purified polyclonal antibody, and more preferably a mAb. Inaddition, it is preferable for the antibody molecules used herein be inthe form of Fab, Fab′, F(ab′)₂ or F(v) portions or whole antibodymolecules.

Particularly preferred methods for detecting PMC virus based on theabove methods include enzyme linked immunosorbent assays,radioimmunoassays, immunoradiometric assays and immunoenzymatic assays,including sandwich assays using monoclonal and/or polyclonal antibodies.

Three such procedures that are especially useful utilise either PMCvirus amino acid sequences (or fragments thereof) labelled with adetectable label, antibody Ab₁ labelled with a detectable label, orantibody Ab₂ labelled with a detectable label. The procedures may besummarized by the following equations wherein the asterisk indicatesthat the particle is labelled and “AA” stands for the PMC virus aminoacid sequence:

-   -   A. AA*+Ab₁=AA*Ab₁    -   B. AA+Ab*₁=AA Ab₁*    -   C. AA+Ab₁+Ab₂*=Ab₁ AA Ab₂*

The procedures and their application are all familiar to those skilledin the art and accordingly may be utilised within the scope of thepresent invention. The “competitive” or “blocking” procedure, ProcedureA, is described in U.S. Pat. Nos. 3,654,090 and 3,850,752. Procedure Bis representative of well-known competitive assay techniques. ProcedureC, the “sandwich” procedure, is described in U.S. Pat. Nos. RE 31,006and 4,016,043. Still other procedures are known, such as the “doubleantibody” or “DASP” procedure.

In each instance, the PMC virus amino acid sequences form complexes withone or more antibody(ies) or binding partners and one member of thecomplex is labelled with a detectable label. The fact that a complex hasformed and, if desired, the amount thereof, can be determined by knownmethods applicable to the detection of labels.

It will be seen from the above that a characteristic property of Ab₂ isthat it will react with Ab₁. This is because Ab₁, raised in onemammalian species, has been used in another species as an antigen toraise the antibody, Ab₂. For example, Ab₂ may be raised in goats usingrabbit antibodies as antigens. Ab₂ therefore would be anti-rabbitantibody raised in goats. For purposes of this description and claims,Ab₁ will be referred to as a primary antibody, and Ab₂ will be referredto as a secondary or anti-Ab₁ antibody.

The labels most commonly employed for these studies are radioactiveelements, enzymes, chemicals that fluoresce when exposed to ultravioletlight, and others.

A number of fluorescent materials are known and can be utilised aslabels. These include, for example, fluorescein, rhodamine and auramine.A particular detecting material is anti-rabbit antibody prepared ingoats and conjugated with fluorescein through an isothiocyanate.

The PMC virus amino acid sequences or their binding partners can also belabelled with a radioactive element or with an enzyme. The radioactivelabel can be detected by any of the currently available countingprocedures. The preferred isotope may be selected from ³H, ¹⁴C, ³²P,³⁵S, ³⁶Cl, ⁵¹Cr, ⁵⁷Co, ⁵⁸Co, ⁵⁹Fe, ⁹⁰Y, ¹²⁵I, ¹³¹I, and ¹⁸⁶Re.

Enzyme labels are likewise useful, and can be detected by any of thepresently utilized colorimetric, spectrophotometric,fluorospectrophotometric, amperometric or gasometric techniques. Theenzyme is conjugated to the selected particle by reaction with bridgingmolecules such as carbodiimides, diisocyanates, glutaraldehyde and thelike. Many enzymes, which can be used in these procedures, are known andcan be utilized. The preferred enzymes are peroxidase, β-glucuronidase,β-D-glucosidase, β-D-galactosidase, urease, glucose oxidase plusperoxidase and alkaline phosphatase. U.S. Pat. Nos. 3,654,090, 3,850,752and 4,016,043 are referred to by way of example for their disclosure ofalternate labelling material and methods.

In another embodiment of the invention there are provided in vitromethods for evaluating the level of PMC virus antibodies in a biologicalsample comprising the steps of:

-   -   a) detecting the formation of reaction complexes in a biological        sample according to the method noted above; and    -   b) evaluating the amount of reaction complexes formed, which        amount of reaction complexes corresponds to the level of PMC        virus antibodies in the biological sample.

Preferably, the antibody used in the above methods binds to the E0, E1,E2, NS2, NS3, NS4A, NS4B and/or NS5A, NS5B proteins of PMC virus.

In another embodiment of the invention there are provided in vitromethods for evaluating the level of PMC virus polypeptides in abiological sample comprising the steps of:

-   -   a) detecting the formation of reaction complexes in a biological        sample according to the method noted above; and    -   b) evaluating the amount of reaction complexes formed, which        amount of reaction complexes corresponds to the level of PMC        virus polypeptide in the biological sample.

Preferably, the polypeptide used in the above methods encodes the E0,E1, E2, NS2, NS3, NS4A, NS4B and/or NS5A, NS5B proteins of PMC virus.

Further there are provided in vitro methods for monitoring therapeutictreatment of a disease associated with PMC virus in an animal hostcomprising evaluating, as describe above, the levels of PMC virusantibodies in a series of biological samples obtained at different timepoints from an animal host undergoing such therapeutic treatment.

The methods for detecting polypeptides using antibodies, orimmunoassays, according to the present invention may utilize antigensfrom the different domains of the new and unique polypeptide sequencesof the present invention that maintain linear (in case of peptides) andconformational epitopes (in case of polypeptides) recognized byantibodies in the sera from subjects infected with PMC virus.

It is within the scope of the invention to use, for instance, single orspecific oligomeric antigens, dimeric antigens, as well as combinationsof single or specific oligomeric antigens.

The PMC virus antigens of the present invention may be employed invirtually any assay format that employs a known antigen to detectantibodies. Of course, a format that denatures the PMC virusconformational epitope should be avoided or adapted.

A common feature of all of these detection methods is that the antigenis contacted with the test specimen suspected of containing PMC virusantibodies under conditions that permit the antigen to bind to any suchantibody present in the component. Such conditions will typically bephysiologic temperature, pH and ionic strength, using an appropriatepredetermined quantity of antigen. The incubation of the antigen withthe specimen is followed by detection of immune complexes comprised ofthe antigen and antibodies derived from the specimen typically by usinga labelled second antibody that is directed against the immunoglobulinsof the test animal species.

Design of the immunoassays is subject to a great deal of variation, andmany formats are known in the art. Protocols may, for example, use solidsupports, or immunoprecipitation. Assays which amplify the signals fromthe immune complex are also known; examples of which are assays whichutilize biotin and avidin or streptavidin, and enzyme-labelled andmediated immunoassays, such as ELISA assays. Furthermore, theimmunoassay may be, without limitation, in a heterogeneous or in ahomogeneous format, and of a standard or competitive type.

In a heterogeneous format, the polypeptide is typically bound to a solidmatrix or support to facilitate separation of the sample from thepolypeptide after incubation. Examples of solid supports that can beused are nitrocellulose (e.g., in membrane or microtiter well form),polyvinyl chloride (e.g., in sheets or microtiter wells), polystyrenelatex (e.g., in beads or microtiter plates, polyvinylidine fluoride(known as Immunolon™), diazotized paper, nylon membranes, activatedbeads, and Protein A beads. For example, Dynatech Immunolon™ 1 orImmunlon™ 2 microtiter plates or 0.25 inch polystyrene beads (PrecisionPlastic Ball) can be used in the heterogeneous format. The solid supportcontaining the antigenic polypeptides is typically washed afterseparating it from the test sample, and prior to detection of boundantibodies. Both standard and competitive formats are know in the art.

In a homogeneous format, the test sample is incubated with thecombination of antigens in solution. For example, it may be underconditions that will precipitate any antigen-antibody complexes whichare formed. Both standard and competitive formats for these assays areknown in the art.

In a standard format, the amount of PMC virus antibodies in theantibody-antigen complexes is directly monitored. This may beaccomplished by determining whether labelled anti-xenogeneic (e.g.anti-swine) antibodies which recognize an epitope on anti-PMC virusantibodies will bind due to complex formation. In a competitive format,the amount of PMC virus antibodies in the sample is deduced bymonitoring the competitive effect on the binding of a known amount oflabelled antibody (or other competing ligand) in the complex.

Complexes formed comprising anti-PMC virus antibody (or in the case ofcompetitive assays, the amount of competing antibody) are detected byany of a number of known techniques, depending on the format. Forexample, unlabelled PMC virus antibodies in the complex may be detectedusing a conjugate of anti-xenogeneic Ig complexed with a label (e.g. anenzyme label).

In an immunoprecipitation or agglutination assay format, the reactionbetween the PMC virus antigens and the antibody forms a network thatprecipitates from the solution or suspension and forms a visible layeror film of precipitate. If no anti-PMC antibody is present in the testspecimen, no visible precipitate is formed.

There currently exist three specific types of particle agglutination(PA) assays. These assays are used for the detection of antibodies tovarious antigens when coated to a support. One type of this assay is thehaemagglutination assay using red blood cells (RBCs) that are sensitizedby passively adsorbing antigen (or antibody) to the RBC. The addition ofspecific antigen antibodies present in the body component, if any,causes the RBCs coated with the purified antigen to agglutinate.

To eliminate potential non-specific reactions in the haemagglutinationassay, two artificial carriers may be used instead of RBC in the PA. Themost common of these are latex particles. However, gelatin particles mayalso be used. The assays utilizing either of these carriers are based onpassive agglutination of the particles coated with purified antigens.

Nucleic Acid-Based Diagnostics

The present invention further provides methods for detecting thepresence or absence of PMC virus in a biological sample, which comprisethe steps of:

-   -   c) bringing the biological sample into contact with a        polynucleotide probe or primer comprising a PMC virus        polynucleotide of the invention under suitable hybridising        conditions; and    -   d) detecting any duplex formed between the probe or primer and        nucleic acid sequences in the sample.

According to one embodiment of the invention, detection of PMC virus maybe accomplished by directly amplifying PMC virus polynucleotidesequences from biological sample, using known techniques and thendetecting the presence of PMC virus polynucleotide sequences.

The present invention thus also relates to a method for the detection ofPMC virus nucleic acids present in a biological sample, comprising:

-   -   c) amplifying the nucleic acid with at least one primer as        defined above,    -   d) detecting the amplified nucleic acids.

Preferably, the nucleic acid is extracted and/or purified (eg from afrom a tissue sample) prior to amplification.

The present invention also relates to a method for the detection of PMCvirus nucleic acids present in a biological sample, comprising:

-   -   d) hybridizing the nucleic acids of the biological sample at        appropriate conditions with one or more probes as defined above,    -   e) washing under appropriate conditions, and    -   f) detecting the hybrids formed.

Preferably, the hybridizing conditions are denatured conditions.

Preferably, the nucleic acid is extracted and/or purified (eg from afrom a tissue sample) prior to hybridisation. More preferably, thenucleic acid sample is amplified with at least one primer as definedabove, after extraction or at least prior to hybridisation. Preferably,said probes are attached to a solid substrate or detected in a liquidphase by photometric or fluorogenic detection or by other methods ofvisualisation such as by agarose gel electrophoresis.

The present invention also relates to a method as defined above, whereinsaid nucleic acids are labelled during or after amplification.

Suitable assay methods for purposes of the present invention to detecthybrids formed between the oligonucleotide probes and the nucleic acidsequences in a sample may comprise any of the assay formats known in theart, such as the conventional dot-blot format, sandwich hybridization orreverse hybridization. For example, the detection can be accomplishedusing a dot blot format, the unlabelled amplified sample being bound toa membrane, the membrane being incorporated with at least one labelledprobe under suitable hybridization and wash conditions, and the presenceof bound probe being monitored.

An alternative and preferred method is a “reverse” dot-blot format, inwhich the amplified sequence contains a label. In this format, theunlabelled oligonucleotide probes are bound to a solid support andexposed to the labelled sample under appropriate stringent hybridizationand subsequent washing conditions. It is to be understood that also anyother assay method which relies on the formation of a hybrid between thenucleic acids of the sample and the oligonucleotide probes according tothe present invention may be used.

In one form of the invention, the target nucleic acid sequence isamplified by PCR and then detected using any of the specific methodsmentioned above. Other useful diagnostic techniques for detecting thepresence of PMC virus polynucleotide sequences include, but are notlimited to: 1) allele-specific PCR; 2) single stranded conformationanalysis; 3) denaturing gradient gel electrophoresis; 4) RNaseprotection assays; 5) the use of proteins which recognize nucleotidemismatches, such as the E. coli mutS protein; 6) allele-specificoligonucleotides; and 7) fluorescent in situ hybridisation.

In addition to the above methods, PMC virus polynucleotide sequences maybe detected using conventional probe technology. When probes are used todetect the presence of the PMC virus polynucleotide sequences, thebiological sample to be analysed, such as blood or serum, may betreated, if desired, to extract the nucleic acids. The samplepolynucleotide sequences may be prepared in various ways to facilitatedetection of the target sequence; e.g. denaturation, restrictiondigestion, electrophoresis or dot blotting. The targeted region of thesample polynucleotide sequence usually must be at least partiallysingle-stranded to form hybrids with the targeting sequence of theprobe. If the sequence is naturally single-stranded, denaturation willnot be required. However, if the sequence is double-stranded, thesequence will probably need to be denatured. Denaturation can be carriedout by various techniques known in the art.

Sample polynucleotide sequences and probes are incubated underconditions that promote stable hybrid formation of the target sequencein the probe with the putative PMC virus polynucleotide sequence in thesample. Preferably, high stringency conditions are used in order toprevent false positives.

Detection, if any, of the resulting hybrid is usually accomplished bythe use of labelled probes. Alternatively, the probe may be unlabelled,but may be detectable by specific binding with a ligand that islabelled, either directly or indirectly. Suitable labels and methods forlabelling probes and ligands are known in the art, and include, forexample, radioactive labels which may be incorporated by known methods(e.g., nick translation, random priming or kinasing), biotin,fluorescent groups, chemiluminescent groups (e.g., dioxetanes,particularly triggered dioxetanes), enzymes, antibodies and the like.Variations of this basic scheme are known in the art, and include thosevariations that facilitate separation of the hybrids to be detected fromextraneous materials and/or that amplify the signal from the labelledmoiety.

It is also contemplated within the scope of this invention that thenucleic acid probe assays of this invention may employ a cocktail ofnucleic acid probes and/or primers capable of detecting PMC viruspolynucleotide sequences. Thus, in one example to detect the presence ofPMC virus polynucleotide sequences in a cell sample, more than one probecomplementary to PMC virus polynucleotide sequences is employed and inparticular the number of different probes is alternatively 2, 3, or 5different nucleic acid probe sequences.

Additionally, the present invention provides a method for detectingviral RNA or DNA comprising the steps of:

-   -   a) immobilizing PMC virus on a support (e.g., a nitrocellulose        filter);    -   b) disrupting the virion; and    -   c) hybridizing with a probe.

Preferably, the probe is labelled. More preferably, the probe isradiolabelled or fluorescent- or enzyme-labelled. Such an approach todetection of virus has already been developed for Hepatitis B virus inperipheral blood (Scotto J. et al. Hepatology (1983), 3, 379-384).

The present invention also provides a method for rapid screening ofgenomic DNA derived from the tissue of subjects with PMC virus relatedsymptoms to detect proviral PMC virus related DNA or RNA present in thetissues. Thus, the present invention also provides a method forscreening the tissue of subjects comprising the steps of:

-   -   a) extracting DNA from tissue;    -   b) restriction enzyme cleavage of said DNA;    -   c) electrophoresis of the fragments; and    -   d) Southern blotting of genomic DNA from tissues and subsequent        hybridization with labelled cloned PMC virus DNA.

Hybridization in situ can also be used.

Antigenic Polypeptide Production

Viral RNA and DNA according to the invention can be used for expressingPMC viral antigens for diagnostic purposes, as well as for theproduction of a vaccine against PMC virus. The methods which can be usedto achieve expression of antigenic polypeptides are multifold:

a) DNA can be transfected into mammalian cells with appropriateselection markers by a variety of techniques, such as calcium phosphateprecipitation, polyethylene glycol, protoplast-fusion, etc and theresultant proteins purified.

b) DNA fragments corresponding to genes can be cloned into expressionvectors for E. coli, yeast or mammalian cells and the resultant proteinspurified.

c) The provival RNA or DNA can be “shot-gunned” (fragmented) intoprokaryotic expression vectors to generate fusion polypeptides.Recombinants, producing antigenically competent fusion proteins, can beidentified by simply screening the recombinants with antibodies againstPMC virus antigens.

Particular reference in this respect is made to those portions of thegenome of PMC virus which, in the figures, are shown to belong to openreading frames and which encode the products having the polypeptidesequences shown. Preferably, the nucleic acid sequences used in theabove methods encode the E0, E1, E2, NS2, NS3, NS4A, NS4B and/or NS5A,NS5B proteins of PMC. Preferably, polypeptides are provided containingsequences in common with polypeptides comprising antigenic determinantsincluded in the proteins encoded and expressed by the PMC virus genome.

Antibodies

Antibodies to PMC Proteins

The different peptides according to this invention can also be usedthemselves for the production of antibodies, preferably monoclonalantibodies specific for the respective different peptides. Thus,according to the invention, PMC virus amino acid sequences producedrecombinantly or by chemical synthesis and fragments or otherderivatives or analogues thereof, including fusion proteins, may be usedas an immunogen to generate antibodies that recognize the PMC virusamino acid sequence. Such antibodies include but are not limited topolyclonal, monoclonal, chimeric, single chain, Fab fragments and a Fabexpression library.

Thus, the present invention provides a method for the generation ofantibodies comprising the steps of:

-   -   a) providing a PMC virus polypeptide sequence to a subject; and    -   b) collecting the antibodies generated in the subject against        the polypeptide.

Preferably, the polypeptide used to generate the antibody is antigenic.More preferably, the polypeptide is chosen from the list comprising theE0, E1, E2, NS2, NS3, NS4A, NS4B and/or NS5A or NS5B proteins of PMCvirus. More preferably, the protein used to generate the antibody is theE0, E2, NS2 and/or NS3 proteins or a fragment or derivative thereof. Forexample, in a highly preferred embodiment, a composition of theinvention comprises both a PMC virus E0/E2 complex and an PMC virusNS2/NS3 complex.

A molecule is “antigenic” when it is capable of specifically interactingwith an antigen recognition molecule of the immune system, such as animmunoglobulin (antibody) or T cell antigen receptor. An antigenic aminoacid sequence contains at least about 5, and preferably at least about10, amino acids. An antigenic portion of a molecule can be that portionthat is immunodominant for antibody or T cell receptor recognition, orit can be a portion used to generate an antibody to the molecule byconjugating the antigenic portion to a carrier molecule forimmunization. A molecule that is antigenic need not be itselfimmunogenic, i.e., capable of eliciting an immune response without acarrier.

An “antibody” is any immunoglobulin, including antibodies and fragmentsthereof, that binds a specific epitope. The term encompasses polyclonal,monoclonal, and chimeric antibodies, the last mentioned described infurther detail in U.S. Pat. Nos. 4,816,397 and 4,816,567, as well asantigen binding portions of antibodies, including Fab, F(ab′)₂ and F(v)(including single chain antibodies). Accordingly, the phrase “antibodymolecule” in its various grammatical forms as used herein contemplatesboth an intact immunoglobulin molecule and an immunologically activeportion of an immunoglobulin molecule containing the antibody combiningsite. An “antibody combining site” is that structural portion of anantibody molecule comprised of heavy and light chain variable andhypervariable regions that specifically binds antigen.

Exemplary antibody molecules are intact immunoglobulin molecules,substantially intact immunoglobulin molecules and those portions of animmunoglobulin molecule that contain the paratope, including thoseportions known in the art as Fab, Fab′, F(ab′)₂ and F(v), which portionsare preferred for use in the therapeutic methods described herein.

Fab and F(ab′)₂ portions of antibody molecules are prepared by theproteolytic reaction of papain and pepsin, respectively, onsubstantially intact antibody molecules by methods that are well-known.See for example, U.S. Pat. No. 4,342,566 to Theofilopolous et al. Fab′antibody molecule portions are also well-known and are produced fromF(ab′)₂ portions followed by reduction with mercaptoethanol of thedisulfide bonds linking the two heavy chain portions, and followed byalkylation of the resulting protein mercaptan with a reagent such asiodoacetamide. An antibody containing intact antibody molecules ispreferred herein.

The phrase “monoclonal antibody” in its various grammatical forms refersto an antibody having only one species of antibody combining sitecapable of immunoreacting with a particular antigen. A monoclonalantibody thus typically displays a single binding affinity for anyantigen with which it immunoreacts.

For the production of hybridomas secreting said monoclonal antibodies,conventional production and screening methods can be used. Thesemonoclonal antibodies, which themselves are part of the invention,provide very useful tools for the identification and even determinationof relative proportions of the different polypeptides or proteins inbiological samples, particularly animals samples containing PMC virus orrelated viruses.

Adjuvants include, but are not limited to, complete Freund's adjuvant,incomplete Freund's adjuvant, saponin, mineral gels such as aluminiumhydroxide, surface active substances such as lysolecithin, pluronicpolyols, polyanions, peptides, oil or hydrocarbon emulsions, keyholelimpet hemocyanins, dinitrophenol, and potentially useful humanadjuvants such as BCG (bacille Calmette-Guerin) and Corynebacteriumparvum. Preferably, the adjuvant is pharmaceutically acceptable.

Further examples of adjuvants which may be effective include but are notlimited to: N-acetyl-muramyl-L-threonyl-D-isoglutamine (thr-MDP),N-acetyl-nor-muramyl-L-alanyl-D-isoglutamine (CGP 11637, referred to asnor-MDP),N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine-2-(1′-2′-dipalmitoyl-sn-glycero-3-hydroxyphosphoryloxy)-ethylamine(CGP 19835A, referred to as MTP-PE), and RIBI, which contains threecomponents extracted from bacteria, monophosphoryl lipid A, trehalosedimycolate and cell wall skeleton (MPL+TDM+CWS) in a 2% squalene/Tween80 emulsion.

Additional examples of adjuvants and other agents include aluminiumhydroxide, aluminium phosphate, aluminium potassium sulfate (alum),beryllium sulfate, silica, kaolin, carbon, water-in-oil emulsions,oil-in-water emulsions, muramyl dipeptide, bacterial endotoxin, lipid X,Corynebacterium parvum (Propionobacterium acnes), Bordetella pertussis,polyribonucleotides, sodium alginate, lanolin, lysolecithin, vitamin A,saponin, immuno stimulating complexes (ISCOMs), liposomes, levamisole,DEAE-dextran, blocked copolymers or other synthetic adjuvants. Suchadjuvants are available commercially from various sources, for example,Merck Adjuvant 65 (Merck and Company, Inc., Rahway, N.J.) or Freund'sIncomplete Adjuvant and Complete Adjuvant (Difco Laboratories, Detroit,Mich.).

Typically, adjuvants such as Amphigen (oil-in-water), Alhydrogel(aluminium hydroxide), or a mixture of Amphigen and Alhydrogel are used.Only aluminium hydroxide is approved for human use.

The proportion of immunogenic polypeptide and adjuvant can be variedover a broad range so long as both are present in effective amounts. Forexample, aluminium hydroxide can be present in an amount of about 0.5%of the vaccine mixture (Al₂O₃ basis). Conveniently, the vaccines areformulated to contain a final concentration of immunogen in the range offrom 0.2 to 200 μg/ml, preferably 5 to 50 μg/ml, most preferably 15μg/ml.

After formulation, the vaccine may be incorporated into a sterilecontainer which is then sealed and stored at a low temperature, forexample 4° C., or it may be freeze-dried. Lyophilisation permitslong-term storage in a stabilised form.

The vaccines are conventionally administered parenterally, by injection,for example, either subcutaneously or intramuscularly. Additionalformulations which are suitable for other modes of administrationinclude suppositories and, in some cases, oral formulations. Forsuppositories, traditional binders and carriers may include, forexample, polyalkylene glycols or triglycerides; such suppositories maybe formed from mixtures containing the active ingredient in the range of0.5% to 10%, preferably 1% to 2%. Oral formulations include suchnormally employed excipients as, for example, pharmaceutical grades ofmannitol, lactose, starch, magnesium stearate, sodium saccharine,cellulose, magnesium carbonate, and the like. These compositions takethe form of solutions, suspensions, tablets, pills, capsules, sustainedrelease formulations or powders and contain 10% to 95% of activeingredient, preferably 25% to 70%. Where the vaccine composition islyophilised, the lyophilised material may be reconstituted prior toadministration, e.g. as a suspension. Reconstitution is preferablyeffected in buffer

Capsules, tablets and pills for oral administration to a patient may beprovided with an enteric coating comprising, for example, Eudragit “S”,Eudragit “L”, cellulose acetate, cellulose acetate phthalate orhydroxypropylmethyl cellulose.

The PMC virus polypeptides of the invention may be formulated into thevaccine as neutral or salt forms. Pharmaceutically acceptable saltsinclude the acid addition salts (formed with free amino groups of thepeptide) and which are formed with inorganic acids such as, for example,hydrochloric or phosphoric acids, or such organic acids such as acetic,oxalic, tartaric and maleic. Salts formed with the free carboxyl groupsmay also be derived from inorganic bases such as, for example, sodium,potassium, ammonium, calcium, or ferric hydroxides, and such organicbases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidineand procaine.

Compositions of the present invention may further comprise antigenicpolypeptides that are not coupled to PMC virus polypeptides and/orbiologically active molecules whose primary purpose is not to serve asan antigen but to modulate the immune response in some other aspect.Examples of biologically molecules that modulate the immune system of ananimal or human subject include cytokines.

The term “cytokine” refers to any secreted polypeptide that influencesthe function of other cells mediating an immune response. Some examplesof cytokines include, but are not limited to, interleukin-1α (IL-1α),interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-3 (IL-3),interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6),interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-9 (1-9),interleukin-10 (IL-10), interleukin-11 (IL-11), interleukin-12 (IL-12),interferon-α (IFN-α), interferon-β (IFN-β), interferon-γ (IFN-γ), tumournecrosis factor-α (TNF-α), tumour necrosis factor-β (TNF-β), granulocytecolony stimulating factor (G-CSF), granulocyte/macrophage colonystimulating factor (GM-CSF), and transforming growth factor-β(TGF-β).

Various procedures known in the art may be used for the production ofpolyclonal antibodies to PMC virus amino acid sequences, or fragment,derivative or analogues thereof.

For the production of antibody, various host animals can be immunised byinjection with the PMC virus amino acid sequence, or a derivative (e.g.,fragment or fusion protein) thereof, including but not limited torabbits, mice, rats, sheep, goats, etc.

In one embodiment, the PMC virus amino acid sequences or fragmentthereof can be conjugated to an immunogenic carrier, e.g., bovine serumalbumin (BSA) or keyhole limpet hemocyanin (KLH).

Various adjuvants may be used to increase the immunological response,depending on the host species, including but not limited to Freund's(complete and incomplete), mineral gels such as aluminum hydroxide,surface active substances such as lysolecithin, pluronic polyols,polyanions, peptides, oil emulsions, keyhole limpet hemocyanins,dinitrophenol, and potentially useful human adjuvants such as BCG(bacille Calmette-Guerin) and Corynebacterium parvum.

For preparation of monoclonal antibodies directed toward the PMC virusamino acid sequences, or fragments, analogues, or derivatives thereof,any technique that provides for the production of antibody molecules bycontinuous cell lines in culture may be used. These include but are notlimited to the hybridoma technique originally developed by Kohler atal., (1975) Nature, 256:495-497, the trioma technique, the human B-cellhybridoma technique [Kozbor et al., (1983) Immunology Today, 4:72], andthe EBV-hybridoma technique to produce human monoclonal antibodies [Coleet al., (1985) in Monoclonal Antibodies and Cancer Therapy, pp. 77-96,Alan R. Liss, Inc.]. Immortal, antibody-producing cell lines can becreated by techniques other than fusion, such as direct transformationof B lymphocytes with oncogenic DNA, or transfection with Epstein-Barrvirus. See, e.g., U.S. Pat. Nos. 4,341,761; 4,399,121; 4,427,783;4,444,887; 4,451,570; 4,466,917; 4,472,500; 4,491,632; and 4,493,890.

In an additional embodiment of the invention, monoclonal antibodies canbe produced in germ-free animals. According to the invention, swineantibodies may be used and can be obtained by using swine hybridomas orby transforming B cells with PMC virus in vitro. In fact, according tothe invention, techniques developed for the production of “chimericantibodies” [Morrison et al., (1984) J. Bacteriol., 159-870; Neubergeret al., (1984) Nature, 312:604-608; Takeda at al., (1985) Nature,314:452-454] by splicing the genes from a mouse antibody moleculespecific for a PMC amino acid sequence together with genes from anantibody molecule of appropriate biological activity can be used; suchantibodies are within the scope of this invention. Such chimericantibodies are preferred for use in therapy of intestinal diseases ordisorders, since the antibodies are much less likely than xenogenicantibodies to induce an immune response, in particular an allergicresponse, themselves.

According to the invention, techniques described for the production ofsingle chain antibodies (U.S. Pat. No. 4,946,778) can be adapted toproduce PMC virus amino acid sequence-specific single chain antibodies.An additional embodiment of the invention utilises the techniquesdescribed for the construction of Fab expression libraries [Huse et al.,(1989) Science, 246:1275-1281] to allow rapid and easy identification ofmonoclonal Fab fragments with the desired specificity for a PMC virusamino acid sequence, or its derivatives, or analogues.

Antibody fragments, which contain the idiotype of the antibody molecule,can be generated by known techniques. For example, such fragmentsinclude but are not limited to: the F(ab′)₂ fragment which can beproduced by pepsin digestion of the antibody molecule; the Fab′fragments which can be generated by reducing the disulfide bridges ofthe F(ab′)₂ fragment, and the Fab fragments which can be generated bytreating the antibody molecule with papain and a reducing agent.

Screening for Antibodies

In the production of antibodies, screening for the desired antibody canbe accomplished by techniques known in the art, e.g., radioimmunoassay,ELISA, “sandwich” immunoassays, immunoradiometric assays, gel diffusionprecipitin reactions, immunodiffusion assays, in situ immunoassays(using colloidal gold, enzyme or radioisotope labels, for example),Western blots, precipitation reactions, agglutination assays (e.g., gelagglutination assays, hemagglutination assays), complement fixationassays, immunofluorescence assays, protein A assays, andimmunoelectrophoresis assays, etc.

In one embodiment, antibody binding is detected by detecting a label onthe primary antibody. In another embodiment, the primary antibody isdetected by detecting binding of a secondary antibody or reagent to theprimary antibody. In a further embodiment, the secondary antibody islabelled. Many means are known in the art for detecting binding in animmunoassay and are within the scope of the present invention. Forexample, to select antibodies that recognise a specific epitope of a PMCvirus amino acid sequence, one may assay generated hybridomas for aproduct that binds to a PMC virus amino acid sequence fragmentcontaining such epitope. For selection of an antibody specific to a PMCvirus amino acid sequence from a particular species of animal, one canselect on the basis of positive binding with PMC virus amino acidsequence expressed by or isolated from cells of that species of animal.

Labelling Antibodies

Advantageously, the labelling of the anti-immunoglobulin antibodies isachieved by an enzyme selected from among those which are capable ofhydrolysing a substrate, which substrate undergoes a modification of itsradiation-absorption, at least within a predetermined band ofwavelengths. The detection of the substrate, preferably comparativelywith respect to a control, then provides a measurement of the likelihoodof exposure of an animal to the virus, or of the effective presence, ofthe disease.

Thus, preferred methods of immunoenzymatic and also immunofluorescentdetections, in particular according to the ELISA technique, areprovided. Titrations may be determinations by immunofluorescence ordirect or indirect immunoenzymatic determinations. Quantitativetitrations of antibodies on the serums studied can be made.

Epitope Bearing Fragments

Antibodies according to the present invention may be generated usingpolypeptide fragments (or molecules, particularly glycoproteins havingthe same polypeptidic backbone as the polypeptides mentionedhereinabove) bearing an epitope characteristic of a protein orglycoprotein of PMC virus. The polypeptide or molecule may further haveN-terminal and C-terminal extremities respectively either free or,independently from each other, covalently bonded to amino acids otherthan those which are normally associated with them in the largerpolypeptides or glycoproteins of the PMC virus, which last mentionedamino acids are then free or belong to another polypeptidic sequence.

Conjugation to Increase Immunogenicity

Peptide sequences of small size bearing an epitope or immunogenicdeterminant, (eg those which are readily generated by chemicalsynthesis), may require coupling or covalent conjugation to aphysiologically acceptable and non-toxic carrier molecule in order toincrease their in vivo immunogenic character and thus enhance theproduction of antibodies.

Particularly, the invention relates to antibodies generated using hybridpolypeptides containing any of the epitope bearing-polypeptides whichhave been defined more specifically hereinabove, recombined with otherpolypeptides fragments normally foreign to the PMC virus proteins,having sizes sufficient to provide increased immunogenicity to theepitope-bearing-polypeptide. The foreign polypeptide fragments arepreferably immunogenically inert and/or do not interfere with theimmunogenic properties of the epitope-bearing-polypeptide.

Such hybrid polypeptides, which may contain from 5 up to 150, even 250amino acids, usually consist of the expression products of a vectorwhich contains a nucleic acid sequence encoding saidepitope-bearing-polypeptide expressible under the control of a suitablepromoter or replicon in a suitable host.

Said epitope-bearing-polypeptides, particularly those whose N-terminaland C-terminal amino acids are free, may also be generated by chemicalsynthesis according to techniques well known in the chemistry ofproteins.

Examples of carrier molecules or macromolecular supports which can beused for making the conjugates according to the invention are naturalproteins, such as tetanic toxoid, ovalbumin, serum-albumins,hemocyanins, etc. Synthetic macromolecular carriers, for examplepolysines or poly(D-L-alanine)-poly(L-lysine), can also be used. Othertypes of macromolecular carriers that can be used, which generally havemolecular weights higher than 20,000, are known from the literature.

The conjugates can be synthesized by known processes such as aredescribed by Frantz and Robertson [Infection & Immunity, 33, 193-198(1981)] and by P. E. Kauffman [pplied and Environmental Microbiology”,October 1981 Vol. 42, No. 4, pp. 611-614]. For instance, the followingcoupling agents can be used: glutaric aldehyde, ethyl chloroformate,water-soluble carbodiimides such as(N-ethyl-N′(3-dimethylamino-propyl)carbodiimide, HCl), diisocyanates, bis-diazobenzidine, di- andtrichloro-s-triazines, cyanogen bromides and benzaquinone, as well asthe coupling agents mentioned in Scand. J. Immunol., 1978, vol. 8, pp.7-23 (Avrameas, Ternynck, Guesdon).

Any coupling process can be used for bonding one or several reactivegroups of the peptide, on the one hand, and one or several reactivegroups of the carrier, on the other hand. Coupling is advantageouslyachieved between the carboxyl and amine groups carried by the peptideand the carrier in the presence of a coupling agent of the type used inprotein synthesis, e.g., 1-ethyl-3-(3-dimethylaminoproyl)-carbodiimide,N-hydroxybenzotriazole, etc. Coupling between amine groups respectivelyborne by the peptide and the carrier can also be made withglutaraldehyde, for instance, according to the method described byBoquet et al. (1982) Molec. Immunol., 19, 1441-1549, when the carrier ishaemocyanin.

The immunogenicity of epitope-bearing-peptides can also be increased byoligomerisation thereof, for example in the presence of glutaraldehydeor any other suitable coupling agent. In particular, the inventionrelates to the water soluble immunogenic oligomers thus obtained,comprising particularly from 2 to 10 monomer units.

Vaccines

The invention also relates to vaccine compositions whose activeprinciple is a polypeptide or fragment thereof of the present inventioni.e. the hereinabove disclosed polypeptides of PMC virus, fusionpolypeptides or oligopeptides, in association with a suitablepharmaceutically or physiologically acceptable carrier. The presentinvention further provides immunogenic polypeptides, and moreparticularly protective polypeptides, for use in the preparation ofvaccine compositions against PMC or related syndromes.

Thus, the present invention provides a vaccine composition comprising aPMC virus polypeptide or fragment thereof.

Preferably, the polypeptide is an antigenic polypeptide. Morepreferably, the vaccine further comprises a pharmaceutically acceptablecarrier or diluent.

The invention also provides a vaccine composition comprising a PMC virusnucleotide or fragment thereof that encodes for a PMC virus polypeptide.

The term “vaccine” as used herein, refers to mean any composition of theinvention containing PMC virus peptide or polypeptide or nucleotidesequences coding for PMC virus polypeptides having at least oneantigenic determinant which, when administered to a animal, is capableof stimulating an immune response against the antigenic determinant. Itwill be understood that the term vaccine does not necessarily imply thatthe composition will provide a complete protective response. Rather atherapeutic effect will be sufficient.

The phrase “immune response” refers to any cellular process that isproduced in the animal following stimulation with an antigen and isdirected toward the elimination of the antigen from the animal. Theimmune response typically is mediated by one or more populations ofcells characterized as being lymphocytic and/or phagocytic in nature.

A vaccine may generate an immune response that blocks the infectivity,either partially or fully, of an infectious agent. The administration ofthe vaccine of the present invention may be for either a prophylactic ortherapeutic purpose. When provided prophylactically, the vaccine isprovided in advance of any exposure to PMC virus or in advance of anysymptom of any symptoms due to PMC virus infection. The prophylacticadministration of the immunogen serves to prevent or attenuate anysubsequent infection by PMC virus in a mammal or reduce the severity ofinfection and/or symptoms. When provided therapeutically, the vaccine isprovided at (or shortly after) the onset of the infection or at theonset of any symptom of infection or disease caused by PMC virus. Thetherapeutic administration of the vaccine serves to attenuate theinfection or disease.

The immune response generated against an introduced PMC virus peptide orpolypeptide will be dictated by the amino acid constitution of theantigenic peptide or polypeptide. Such determinants may define eitherhumoral or cell mediated antigenic regions. Without being limited to anyparticular mode of action, it is contemplated that the immune responsegenerated by the PMC virus peptide or polypeptide will preferablyinclude both humoral and cell mediated immune responses. Where a cellmediated immune response is effected it preferably leads to a T cellcascade, and more specifically by means of a cytotoxic T cell cascade.

The term “cytotoxic T cell”, as used herein, refers to any T lymphocyteexpressing the cell surface glycoprotein marker CD8+ that is capable oftargeting and lysing a target cell which bears a majorhistocompatibility class I (MHC Class I) complex on its cell surface andis infected with an intracellular pathogen.

Preferably, the vaccine composition is developed to generate antibodiesagainst the E0 and E2 envelope glycoproteins and the NS2 and NS3non-structural proteins.

The vaccine compositions of the present invention may be used tovaccinate animals and humans against infectious diseases, preferablyagainst PMC. The term “animal” includes: mammals such as farm animalsincluding sheep, goats, pigs, cows, horses, llamas, household pets suchas dogs and cats, and primates; birds, such as chickens, geese andducks; fish; and reptiles such as crocodiles and alligators.

The vaccine composition according to the invention preferably contains anucleotide sequence as described above, either as such or as a vaccinestrain or in a vector or host organism, or a polypeptide as describedabove, in an amount effective for producing protection against apestivirus infection. The vaccine can also be a multipurpose vaccinecomprising other immunogens or nucleotides encoding these. The vaccinescan furthermore contain conventional carriers, adjuvants, solubilizers,emulsifiers, preservatives etc. The vaccines according to the inventioncan be prepared by conventional methods.

Preferably, the active principle is a peptide containing less than 250amino acid units, preferably less than 150, particularly from 5 to 150amino acid residues, as deducible from the complete genome of PMC virus.

The term ‘effective amount’ refers to an amount of epitope-bearingpolypeptide sufficient to induce an immunogenic response in the subjectto which it is administered either in a single dose or as part of aseries of doses. Preferably, the effective amount is sufficient toeffect prophylaxis or treatment, as defined above. The exact amountnecessary will vary according to the application. For vaccineapplications or for the generation of polyclonal antiserum/antibodies,for example, the effective amount may vary depending on the taxonomicgroup or species of subject to be treated (e.g. nonhuman primate,primate, etc.), the age and general health and physical condition of thesubject, the severity of the condition being treated, the capacity ofthe subject's immune system to synthesize antibodies, the degree ofprotection desired, the formulation of the vaccine, the strain ofinfecting PMC virus, the particular polypeptide selected and its mode ofadministration, and other relevant factors. It is also believed thateffective amounts will be found within a relatively large, non-criticalrange. An appropriate effective amount can be readily determined usingonly routine experimentation.

By way of example, suitable dosages of the vaccine compositions arethose which are effective to elicit antibodies in vivo, in the host,particularly a porcine host. Suitable doses range from 10 to 500 μg ofpolypeptide, protein or glycoprotein, for instance 50 to 100 μg. Otherpreferred ranges of proteins for prophylaxis of PMC are 0.01 to 1000μg/dose, preferably 0.1 to 100 μg/dose. Several doses may be needed persubject in order to achieve a sufficient immune response and subsequentprotection against PMC.

The immunogenic compositions are conventionally administered usingstandard procedures, for example, intravenously, subcutaneously,intramuscularly, intraorbitally, ophthalmically, intraventricularly,intracranially, intracapsularly, intraspinally, intracisternally,intraperitoneally, buccal, rectally, vaginally, intranasally, orally orby aerosol administration.

Preferably, the immunogenic composition is administered parenterally,typically by injection, for example, subcutaneously or intramuscularly.However, additional formulations suitable for other methods ofadministration include oral formulations and suppositories or preparedfor pulmonary, nasal or other forms of administration. Dosage treatmentmay be a single dose schedule or a multiple dose schedule.

The mode of administration of the immunogenic vaccine compositionsprepared in accordance with the invention will necessarily depend uponsuch factors as the stability of the immunogenic compositions underphysiological conditions, the intensity of the immune response requiredetc.

The vaccine compositions of the invention may be co-administered withadditional immune response enhancers or biological response modifiersincluding, but not limited to, the cytokines IFN-α, IFN-γ, IL-2, IL-4,IL-6, TNF, or other cytokine-affecting immune cells. In accordance withthis aspect of the invention, the PMC virus peptide or polypeptide isadministered in combination therapy with a therapeutically active amountof one or more of these cytokines. In addition, conventional antibioticsmay be coadministered with the PMC virus peptide or polypeptide. Thechoice of suitable antibiotics will however be dependent upon thedisease in question.

Parenteral Delivery

The compounds provided herein can be administered by any parenteraltechniques such as subcutaneous, intravenous and intraperitonealinjections. Typically, such vaccines are prepared either as liquidsolutions or suspensions; solid forms suitable for solution in, orsuspension in, liquid prior to injection may also be prepared. Thepreparation may also be emulsified, or the protein encapsulated inliposomes. The active immunogenic ingredients are often mixed withexcipients and carriers, which are pharmaceutically acceptable andcompatible with the active ingredient. Suitable excipients are, forexample, water, saline, dextrose, glycerol, ethanol, or the like andcombinations thereof.

In addition, if desired, the vaccine may contain minor amounts ofauxiliary substances such as wetting or emulsifying agents, pH bufferingagents, and/or adjuvants which enhance the effectiveness of the vaccine.

Oral Delivery

Contemplated for use herein are oral solid dosage forms, which aredescribed generally in Martin, Remington's Pharmaceutical Sciences, 18thEd. (1990 Mack Publishing Co. Easton Pa. 18042) at Chapter 89, which isherein incorporated by reference. Solid dosage forms include tablets,capsules, pills, troches or lozenges, cachets or pellets. Also,liposomal or proteinoid encapsulation may be used to formulate thepresent compositions (as, for example, proteinoid microspheres reportedin U.S. Pat. No. 4,925,673). Liposomal encapsulation may be used and theliposomes may be derivatised with various polymers (E.g., U.S. Pat. No.5,013,556). A description of possible solid dosage forms for thetherapeutic is given by Marshall, in Modern Pharmaceutics, Chapter 10,Banker and Rhodes ed., (1979), herein incorporated by reference. Ingeneral, the formulation will include a PMC virus polypeptide orpolynucleotide, and inert ingredients which allow for protection againstthe stomach environment, and release of the biologically active materialin the intestine.

Also specifically contemplated are oral dosage forms of PMC viruspolypeptides or polynucleotides. In this respect the PMC viruspolypeptides or polynucleotides may be chemically modified so that oraldelivery is efficacious. Generally, the chemical modificationcontemplated is the attachment of at least one moiety to the protein (orpeptide) molecule itself, where said moiety permits (a) inhibition ofproteolysis; and (b) uptake into the blood stream from the stomach orintestine. Also desired is the increase in overall stability of theprotein and increase in circulation time in the body. Examples of suchmoieties include: polyethylene glycol, copolymers of ethylene glycol andpropylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol,polyvinyl pyrrolidone and polyproline. Abuchowski et al., 1981, supra;Newmark et al., J. Appl. Biochem., 4:185-189 (1982). Other polymers thatcould be used are poly-1,3-dioxolane and poly-1,3,6-tioxocane. Preferredfor pharmaceutical usage, as indicated above, are polyethylene glycolmoieties.

For PMC virus polypeptides or polynucleotides the location of releasemay be the stomach, the small intestine (the duodenum, the jejunem, orthe ileum), or the large intestine. One skilled in the art has availableformulations that will not dissolve in the stomach, yet will release thematerial in the duodenum or elsewhere in the intestine. Preferably, therelease will avoid the deleterious effects of the stomach environment,either by protection of the complex or by release of the biologicallyactive material beyond the stomach environment, such as in theintestine.

To ensure full gastric resistance, a coating impermeable to at least pH5.0 is essential. Examples of the more common inert ingredients that areused as enteric coatings are cellulose acetate trimellitate (CAT),hydroxypropylmethylcellulose phthalate (HPMCP), HPMCP 50, HPMCP 55,polyvinyl acetate phthalate (PVAP), Eudragit L30D, Aquateric, celluloseacetate phthalate (CAP), Eudragit L, Eudragit S, and Shellac. Thesecoatings may be used as mixed films.

A coating or mixture of coatings can also be used on tablets, which arenot intended for protection against the stomach. This can include sugarcoatings, or coatings which make the tablet easier to swallow. Capsulesmay consist of a hard shell (such as gelatin) for delivery of drytherapeutic i.e. powder; for liquid forms, a soft gelatin shell may beused. The shell material of cachets could be thick starch or otheredible paper. For pills, lozenges, molded tablets or tablet triturates,moist massing techniques can be used.

The therapeutic can be included in the formulation as finemultiparticulates in the form of granules or pellets of particle sizeabout 1 mm. The formulation of the material for capsule administrationcould also be as a powder, lightly compressed plugs or even as tablets.The therapeutic could be prepared by compression.

Colorants and flavoring agents may all be included. For example, PMCvirus polypeptides or polynucleotides may be formulated (such as byliposome or microsphere encapsulation) and then further contained withinan edible product, such as a refrigerated beverage containing colorantsand flavoring agents.

One may dilute or increase the volume of the therapeutic with an inertmaterial. These diluents could include carbohydrates, especiallymannitol, alpha-lactose, anhydrous lactose, cellulose, sucrose, modifieddextrans and starch. Certain inorganic salts may be also be used asfillers including calcium triphosphate, magnesium carbonate and sodiumchloride. Some commercially available diluents are Fast-Flo, Emdex,STA-Rx 1500, Emcompress and Avicell.

Disintegrants may be included in the formulation of the therapeutic intoa solid dosage form. Materials used as disintegrants include but are notlimited to starch including the commercial disintegrant based on starch,Explotab. Sodium starch glycolate, Amberlite, sodiumcarboxymethylcellulose, ultramylopectin, sodium alginate, gelatin,orange peel, acid carboxymethyl cellulose, natural sponge and bentonitemay all be used. Another form of the disintegrants are the insolublecationic exchange resins. Powdered gums may be used as disintegrants andas binders and these can include powdered gums such as agar, Karaya ortragacanth. Alginic acid and its sodium salt are also useful asdisintegrants.

Binders may be used to hold the therapeutic agent together to form ahard tablet and include materials from natural products such as acacia,tragacanth, starch and gelatin. Others include methyl cellulose (MC),ethyl cellulose (EC) and carboxymethyl cellulose (CMC). Polyvinylpyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both beused in alcoholic solutions to granulate the therapeutic.

An antifrictional agent may be included in the formulation of thetherapeutic to prevent sticking during the formulation process.Lubricants may be used as a layer between the therapeutic and the diewall and these can include but are not limited to: stearic acidincluding its magnesium and calcium salts, polytetrafluoroethylene(PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricantsmay also be used such as sodium lauryl sulphate, magnesium laurylsulphate, polyethylene glycol of various molecular weights, and Carbowax4000 and 6000.

Glidants that might improve the flow properties of the complex duringformulation and to aid rearrangement during compression might be added.The glidants may include starch, talc, pyrogenic silica and hydratedsilicoaluminate.

To aid dissolution of the therapeutic into the aqueous environment, asurfactant might be added as a wetting agent. Surfactants may includeanionic detergents such as sodium lauryl sulphate, dioctyl sodiumsulphosuccinate and dioctyl sodium sulfonate. Cationic detergents mightbe used and could include benzalkonium chloride or benzethomiumchloride. The list of potential nonionic detergents that could beincluded in the formulation as surfactants are lauromacrogol 400,polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and60, glycerol monostearate, polysorbate 40, 60, 65 and 80, sucrose fattyacid ester, methyl cellulose and carboxymethyl cellulose. Thesesurfactants could be present in the formulation of the complex eitheralone or as a mixture in different ratios.

Additives which potentially enhance uptake of the complex are forinstance the fatty acids oleic acid, linoleic acid and linolenic acid.

Controlled release formulation may be desirable. The complex could beincorporated into an inert matrix which permits release by eitherdiffusion or leaching mechanisms i.e., gums. Slowly degeneratingmatrices may also be incorporated into the formulation. Another form ofa controlled release of this therapeutic is by a method based on theOros therapeutic system (Alza Corp.), i.e. the drug is enclosed in asemipermeable membrane which allows water to enter and push drug outthrough a single small opening due to osmotic effects. Some entericcoatings also have a delayed release effect.

Other coatings may be used for the formulation. These include a varietyof sugars which could be applied in a coating pan. The therapeutic agentcould also be given in a film-coated tablet; the materials used in thisinstance are divided into 2 groups. The first are the nonentericmaterials and include methyl cellulose, ethyl cellulose, hydroxyethylcellulose, methylhydroxy-ethyl cellulose, hydroxypropyl cellulose,hydroxypropyl-methyl cellulose, sodium carboxy-methyl cellulose,providone and the polyethylene glycols. The second group consists of theenteric materials that are commonly esters of phthalic acid.

A mix of materials might be used to provide the optimum film coating.Film coating may be carried out in a pan coater or in a fluidized bed orby compression coating.

Pulmonary Delivery

Also contemplated herein is pulmonary delivery of vaccine composition.The PMC virus polypeptides or polynucleotides may be delivered to thelungs of an animal while inhaling and traverses across the lungepithelial lining to the blood-stream.

Contemplated for use in the practice of this invention are a wide rangeof mechanical devices designed for pulmonary delivery of therapeuticproducts, including but not limited to nebulizers, metered-doseinhalers, and powder inhalers, all of which are familiar to thoseskilled in the art.

Some specific examples of commercially available devices suitable forthe practice of this invention are the Ultravent nebulizer, manufacturedby Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer,manufactured by Marquest Medical Products, Englewood, Colo.; theVentolin metered dose inhaler, manufactured by Glaxo Inc., ResearchTriangle Park, North Carolina; and the Spinhaler powder inhaler,manufactured by Fisons Corp., Bedford, Mass.

All such devices require the use of formulations suitable for thedispensing of the complex. Typically, each formulation is specific tothe type of device employed and may involve the use of an appropriatepropellant material, in addition to the usual diluents, adjuvants and/orcarriers useful in therapy. Also, the use of liposomes, microcapsules ormicrospheres, inclusion complexes, or other types of carriers iscontemplated. Chemically modified proteins may also be prepared indifferent formulations depending on the type of chemical modification orthe type of device employed.

Formulations suitable for use with a nebulizer, either jet orultrasonic, will typically comprise the complex suspended in water at aconcentration of about 0.1 to 25 mg of biologically active protein perml of solution. The formulation may also include a buffer and a simplesugar (e.g., for protein stabilization and regulation of osmoticpressure). The nebulizer formulation may also contain a surfactant, toreduce or prevent surface induced aggregation of the protein caused byatomization of the solution in forming the aerosol.

Formulations for use with a metered-dose inhaler device will generallycomprise a finely divided powder containing the complex suspended in apropellant with the aid of a surfactant. The propellant may be anyconventional material employed for this purpose, such as achlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or ahydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane,dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, orcombinations thereof. Suitable surfactants include sorbitan trioleateand soya lecithin. Oleic acid may also be useful as a surfactant.

Formulations for dispensing from a powder inhaler device will comprise afinely divided dry powder containing the complex and may also include abulking agent, such as lactose, sorbitol, sucrose, or mannitol inamounts which facilitate dispersal of the powder from the device, e.g.,50 to 90% by weight of the formulation. The protein (or derivative)should most advantageously be prepared in particulate form with anaverage particle size of less than 10 microns, most preferably 0.5 to 5microns, for most effective delivery to the distal lung.

Nasal Delivery

Nasal delivery of the vaccine comprising PMC virus polypeptides orpolynucleotides is also contemplated. Nasal delivery allows the passageof the protein to the blood stream directly after administering thetherapeutic product to the nose, without the necessity for deposition ofthe product in the lung. Formulations for nasal delivery include thosewith dextran or cyclodextran.

Therapeutic Compositions

Polypeptide Based Therapies

The PMC virus polypeptides according to present invention also can beused as a prophylactic or therapeutic, which may be utilised for thepurpose of stimulating humoral and cell mediated responses in animals,such as swine, thereby providing protection against infection with PMCvirus. Natural infection with PMC virus induces circulating antibodytitres against PMC virus. Therefore, PMC virus amino acid sequence orparts thereof, have the potential to form the basis of a systemically ororally administered prophylactic or therapeutic to provide protectionagainst PMC.

Thus, the invention provides pharmaceutical compositions comprising aPMC virus polypeptide that enhances the immunocompetence of the hostindividual and elicits specific immunity against pathogens, preferablyPMC virus.

The therapeutic regimens and pharmaceutical compositions of theinvention are described elsewhere in the specification. Thesecompositions are believed to have the capacity to prevent the onset andprogression of infectious disease such as PMC.

Preferably the compositions are combined with a pharmaceuticallyacceptable carrier or diluent to produce a pharmaceutical composition(which may be for human or animal use). Compositions of the inventioncomprising PMC virus polypeptides may also be combined with suitablecomponents to obtain vaccine compositions. Accordingly, in oneembodiment the present invention provides a PMC virus amino acidsequence or fragments thereof described herein in a therapeuticallyeffective amount admixed with a pharmaceutically acceptable carrier,diluent, or excipient.

The phrase “therapeutically effective amount” is used herein to mean anamount sufficient to reduce by at least about 15%, preferably by atleast 50%, more preferably by at least 90%, and most preferably prevent,a clinically significant deficit in the activity, function and responseof the animal host. Alternatively, a therapeutically effective amount issufficient to cause an improvement in a clinically significant conditionin the animal host or to stimulate by at least about 15%, preferably byat least 50%, more preferably by at least 90%, and most preferablycompletely, a animal's immune system, causing it to generate animmunological memory against the antigenic determinant.

The phrase “pharmaceutically acceptable” refers to molecular entitiesand compositions that are physiologically tolerable and do not typicallyproduce an allergic or similarly untoward reaction, such as gastricupset and the like, when administered to an animal. The term “carrier”refers to a diluent, adjuvant, excipient, or vehicle with which thecompound is administered. Such pharmaceutical carriers can be sterileliquids, such as water and oils, including those of petroleum, animal,vegetable or synthetic origin, such as peanut oil, soybean oil, mineraloil, sesame oil and the like. Water or saline solutions and aqueousdextrose and glycerol solutions are preferably employed as carriers,particularly for injectable solutions. Suitable pharmaceutical carriersare described in Martin, Remington's Pharmaceutical Sciences, 18th Ed.,Mack Publishing Co., Easton, Pa., (1990).

In a more specific form of the invention there are providedpharmaceutical compositions comprising therapeutically effective amountsof PMC virus amino acid sequence or an analogue, fragment or derivativeproduct thereof together with pharmaceutically acceptable diluents,preservatives, solubilizes, emulsifiers, adjuvants and/or carriers. Suchcompositions include diluents of various buffer content (e.g., Tris-HCl,acetate, phosphate), pH and ionic strength and additives such asdetergents and solubilizing agents (e.g., Tween 80, Polysorbate 80),anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives(e.g., Thimersol, benzyl alcohol) and bulking substances (e.g., lactose,mannitol). The material may be incorporated into particulatepreparations of polymeric compounds such as polylactic acid,polyglycolic acid, etc. or into liposomes. Hylauronic acid may also beused. Such compositions may influence the physical state, stability,rate of in vivo release, and rate of in vivo clearance of the presentproteins and derivatives. See, e.g., Martin, Remington's PharmaceuticalSciences, 18th Ed. 1990, Mack Publishing Co., Easton, Pa., pp 1435-1712that are herein incorporated by reference. The compositions may beprepared in liquid form, or may be in dried powder, such as lyophilisedform.

The present invention also provides for the use of PMC virus amino acidsequences according to the invention, for manufacture of a medicamentfor modulation of a disease associated with PMC virus.

Antibody Based Therapeutics

The present invention also provides therapeutic compositions comprisingantibodies prepared against the polypeptides of the invention.

The antibodies can be used directly as antiviral agents. To prepareantibodies, a host animal is immunized using one or more PMC virusproteins bound to a carrier as described above for vaccines. The hostserum or plasma is collected following an appropriate time interval toprovide a composition comprising antibodies reactive with the protein(s)of the virus particle. The gamma globulin fraction or the IgG antibodiescan be obtained, for example, by use of saturated ammonium sulfate orDEAE Sephadex, or other techniques known to those skilled in the art.The antibodies are substantially free of many of the adverse sideeffects which may be associated with other anti-viral agents such asdrugs.

Such therapeutic antibody compositions may additionally contain one ormore of the additional agents described above in relation to polypeptidetherapeutics.

The present invention provides for the use of antibodies against the PMCvirus according to the invention, for manufacture of a medicament formodulation of a disease associated with PMC virus.

Polynucleotide Based Therapy

The present invention further provides therapeutic compositionscomprising PMC virus nucleic acid sequences as well as antisense andribozyme polynucleotide sequences hybridisable to a polynucleotidesequence encoding a PMC virus amino acid sequence according to theinvention.

Polynucleotide sequences encoding antisense constructs or ribozymes foruse in therapeutic methods are desirably administered directly as anaked nucleic acid construct. Uptake of naked nucleic acid constructs isenhanced by several known transfection techniques, for example thoseincluding the use of transfection agents. Example of these agentsinclude cationic agents (for example calcium phosphate and DEAE-dextran)and lipofectants (for example Iipofectam™ and Transfectam™). Typically,nucleic acid constructs are mixed with the transfection agent to producea composition.

Alternatively the antisense construct or ribozymes may be combined witha pharmaceutically acceptable carrier or diluent to produce apharmaceutical composition. Suitable carriers and diluents includeisotonic saline solutions, for example phosphate-buffered saline. Thecomposition may be formulated for parenteral, intramuscular,intravenous, subcutaneous, intraocular, oral or transdermaladministration.

Also addressed by the present invention is the use of polynucleotidesequences of the invention, as well as antisense and ribozymepolynucleotide sequences hybridisable to a polynucleotide sequenceencoding a PMC virus amino acid sequence according to the invention, formanufacture of a medicament for modulation of a disease associated withPMC virus.

Administration of Therapeutic Compositions

It will be appreciated that therapeutic compositions providedaccordingly to the invention may be administered by any means known inthe art. Therapeutic compositions may be for administration byinjection, or prepared for oral, pulmonary, nasal or other forms ofadministration. The mode of administration of the therapeuticcompositions prepared in accordance with the invention will necessarilydepend upon such factors as the stability of the complex underphysiological conditions, the intensity of the immune response requiredetc.

Preferably, the pharmaceutical compositions for administration areadministered by injection, orally, or by the pulmonary, or nasal route.

Preferably, the therapeutic compositions are administered using standardprocedures, for example, intravenously, subcutaneously, intramuscularly,intraorbitally, ophthalmically, intraventricularly, intracranially,intracapsularly, intraspinally, intracisternally, intraperitoneally,buccal, rectally, vaginally, intranasally, orally or by aerosoladministration.

The PMC virus amino acid sequence or antibodies derived there from, orpolynucleotide sequences are more preferably delivered by intravenous,intra-arterial, intraperitoneal, intramuscular, or subcutaneous routesof administration. Alternatively, the PMC virus amino acid sequence orantibodies derived there from, properly formulated, can be administeredby nasal or oral administration. The routes of administration describedare intended only as a guide since a skilled practitioner will be ableto determine readily the optimum route of administration and any dosagefor any particular animal and condition.

The present invention further provides a method of inducing a protectiveimmune response in an animal or human against a PMC virus comprising thesteps of:

-   -   a) administering to said animal or human an effective amount of        a composition of the invention.

The present invention also provides methods for enhancing an animal'simmunocompetence and the activity of its immune effector cells against aPMC virus comprising the step of:

-   -   a) administering a composition comprising a therapeutically        effective amount of a PMC virus peptide or polypeptide.        Live Vector Delivery Agent

In another aspect of the invention, the PMC virus may be used as a livevector for delivery of recombinant antigens.

Thus, the present invention provides a live vector comprising the PMCvirus and a heterologous polynucleotide.

Preferably, the heterlolgous polynucleotide is operably linked to thepolyneucletide sequence of the PMC virus, such that expression of thepolynucleotide sequence of the PMC virus also leads to expression of theheterologous polynucleotide sequence.

Furthermore, the PMC virus may have one or more sections of autologouspolynucleotide sequence removed. Removal of such sequence may preferablyrender the live virus attenuated in pathogenicity in a host subject.

For example, the PMC virus may be used as a delivery vector to delivergene sequences that encode a protein from a second infective agent intoa subject to be vaccinated against the second infective agent. Thesecond infective agent may be a virus (such as classical swine fevervirus), a bacteria, a parasite etc.

Alternatively, the PMC virus may be used as a delivery vector to deliverantigens from some other source. For example, a PMC virus vector may beused to deliver antigenic proteins to a subject to stimulate the subjectto make antibodies against the antigenic proteins that may be collectedfor purposes such as use in diagnostic kits etc.

Drug Screening Assays

The present invention also provides assays that are suitable foridentifying substances such as drugs, agents or ligands that bind to PMCvirus amino acid sequences. In addition, assays are provided that aresuitable for identifying substances that interfere with PMC virus aminoacid sequences. Assays are also provided that test the effects ofcandidate substances identified in preliminary in vitro assays on intactcells in whole cell assays.

Thus, the present invention provides a method of screening for drugscomprising the steps of:

-   -   a) contacting an agent with a PMC virus amino acid sequence or        fragment thereof and    -   b) assaying for the presence of a complex between the agent and        the PMC virus amino acid sequence or fragment.

The present invention also provides a method of screening for ligands ofthe proteins of the PMC virus comprising the steps of:

-   -   a) contacting a ligand with a PMC virus amino acid sequence or        fragment thereof and    -   b) assaying for the presence of a complex between the PMC virus        amino acid sequence or fragment and a ligand.

One type of assay for identifying substances such as drugs, agents orligands that bind to PMC virus amino acid sequences involves contactinga PMC virus amino acid sequence, which is immobilised on a solidsupport, with a non-immobilised candidate substance and determiningwhether and/or to what extent the PMC virus amino acid sequences andcandidate substance bind to each other. Alternatively, the candidatesubstance may be immobilised and the PMC virus amino acid sequencenon-immobilised.

In a preferred assay method, the PMC virus amino acid sequence isimmobilised on beads such as agarose beads. Typically this is achievedby expressing the component as a GST-fusion protein in bacteria, yeastor higher eukaryotic cell lines and purifying the GST-fusion proteinfrom crude cell extracts using glutathione-agarose beads. The binding ofthe candidate substance to the immobilised PMC virus amino acid sequenceis then determined. This type of assay is known in the art as a GSTpulldown assay. Again, the candidate substance may be immobilised andthe PMC virus amino acid sequence non-immobilised.

It is also possible to perform this type of assay using differentaffinity purification systems for immobilising one of the components,for example Ni-NTA agarose and hexahistidine-tagged components.

Binding of the PMC virus amino acid sequence to the candidate substancemay be determined by a variety of methods well known in the art. Forexample, the non-immobilised component may be labelled (with forexample, a radioactive label, an epitope tag or an enzyme-antibodyconjugate). Alternatively, binding may be determined by immunologicaldetection techniques. For example, the reaction mixture can be Westernblotted and the blot probed with an antibody that detects thenon-immobilised component. ELISA techniques may also be used.

Candidate substances are typically added to a final concentration offrom 1 to 1000 nmol/ml, more preferably from 1 to 100 nmol/ml. In thecase of antibodies, the final concentration used is typically from 100to 500 μg/ml, more preferably from 200 to 300 μg/ml.

In a competitive binding assay the PMC virus amino acid sequence orfragment is typically labelled. Free PMC virus amino acid sequence orfragment is separated from that present in a protein:protein complex,and the amount of free (i.e., uncomplexed) label is a measure of thebinding of the agent being tested to the PMC virus amino acid sequenceor its interference with PMC virus amino acid sequence: ligand binding,respectively.

Another technique for drug screening provides high throughput screeningfor compounds having suitable binding affinity to the PMC virus aminoacid sequence and is described in detail in PCT Application WO 84/03564,published on Sep. 13, 1984. Briefly stated, large numbers of differentsmall peptide test compounds are synthesised on a solid substrate, suchas plastic pins or some other surface. The peptide test compounds arereacted with PMC virus amino acid sequence and washed. Bound PMC virusamino acid sequence is then detected by methods well known in the art.

This invention also contemplates the use of competitive drug screeningassays in which antibodies capable of specifically binding the PMC virusamino acid sequence compete with a test compound for binding to the PMCvirus amino acid sequence or fragments thereof. In this manner, theantibodies can be used to detect the presence of any peptide that sharesone or more antigenic determinants of the PMC virus amino acid sequence.

Kits

In a further embodiment of this invention, kits may be prepared todetermine the presence or absence of PMC virus in suspected infectedanimals and/or to quantitatively measure PMC infection. In accordancewith the testing techniques discussed above, one class of such kits willcontain at least the labelled PMC virus amino acid sequence or itsbinding partner, for instance an antibody specific thereto, anddirections depending upon the method selected, e.g., “competitive,”“sandwich,” “DASP” and the like. The kits may also contain peripheralreagents such as buffers, stabilizers, etc.

Thus, kits for PMC virus serum immunoassay may be either (a) a sandwichtype immunoassay, employing a first anti-PMC virus antibody as captureor detector antibody and a second anti-PMC virus antibody as a detectoror capture antibody to complement the first anti-PMC virus antibody, or(b) a competitive type immunoassay, employing a anti-PMC virus antibodywith a labelled PMC virus antigen or a PMC virus antigen attached to asolid phase.

Accordingly, a test kit may be prepared for the demonstration of thepresence of PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled        immunochemically reactive component obtained by the direct or        indirect attachment of the present PMC virus amino acid sequence        or a specific binding partner thereto, to a detectable label;    -   (b) other reagents; and    -   (c) directions for use of said kit.

More specifically, the diagnostic test kit may comprise:

-   -   (a) a known amount of the PMC virus amino acid sequence as        described above (or a binding partner) generally bound to a        solid phase to form an immunosorbent, or in the alternative,        bound to a suitable tag, or there are a plural of such end        products, etc;    -   (b) if necessary, other reagents; and    -   (c) directions for use of said test kit.

In a further variation, the test kit may be prepared and used for thepurposes stated above, which operates according to a predeterminedprotocol (e.g. “competitive,” “sandwich,” “double antibody,” etc.), andcomprises:

-   -   (a) a labelled component which has been obtained by coupling the        PMC virus amino acid sequence to a detectable label;    -   (b) one or more additional immunochemical reagents of which at        least one reagent is a ligand or an immobilized ligand, which        ligand is selected from the group consisting of:        -   (i) a ligand capable of binding with the labelled component            (a);        -   (ii) a ligand capable of binding with a binding partner of            the labelled component (a);        -   (iii) a ligand capable of binding with at least one of the            component(s) to be determined; or        -   (iv) a ligand capable of binding with at least one of the            binding partners of at least one of the component(s) to be            determined; and    -   (c) directions for the performance of a protocol for the        detection and/or determination of one or more components of an        immunochemical reaction between the PMC virus amino acid        sequence and a specific binding partner thereto.        Kits to Detect Antibodies

The invention also provides diagnostic kits for the in vitro detectionof antibodies against the PMC virus, which kits comprise any of thepolypeptides identified herein and all the biological and chemicalreagents, as well as equipment, necessary for performing diagnosticassays.

Accordingly, the invention provides a kit for demonstrating the presenceof PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled antibody to        the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

Preferably, the polypeptide used in the kit is an antigenic or epitopebearing polypeptide. Most preferably, the polypeptide is a polypeptideencoding, but not exclusively limited to, the E0, E2, NS2 or NS3protein.

Preferred kits comprise all reagents required for carrying out ELISAassays. Thus preferred kits will include, in addition to any of saidpolypeptides, suitable buffers and anti-species immunoglobulins, whichanti-species immunoglobulins are labelled either by an immunofluorescentmolecule or by an enzyme. In the last instance, preferred kits alsocomprise a substrate hydrolysable by the enzyme and providing a signal,particularly modified absorption of a radiation, at least in adetermined wavelength, which signal is then indicative of the presenceof antibody in the biological fluid to be assayed with said kit. Kitsmay also include labelled monoclonal or polyclonal antibodies that aredirected against PMC virus epitopes and these labelled antibodies may beused to block or compete with antibodies from the test specimen. If theactivity of the labelled antibody is blocked, no or a reduced reactionwill occur and it can be deduced that the test specimen containsantibodies to PMC virus.

The present invention also relates to a diagnostic kit for use indetecting the presence of PMC virus antibodies, said kit comprising atleast one peptide as defined above, with said peptide being preferablybound to a solid support.

The peptide, for example, can be attached to a variety of differentsolid supports to enable the washing away of unreacted reagents duringthe course of using the kit. These include: microwells, coated testtubes, coated magnetic particles, wands or sticks, and membranes(nitrocellulose and others).

Preferably, the peptides are attached to specific locations on the solidsupport. More preferably, the solid support is a membrane strip and saidpeptides are coupled to the membrane in the form of parallel lines.Preferably, the peptide used in the kit is an antigenic or epitopebearing peptide.

The PMC virus antigens of the present invention will typically bepackaged in the form of a kit for use in these immunoassays. The kitwill normally contain, in separate containers, the PMC virus antigen,control antibody formulations (positive and/or negative), labelledantibody when the assay format requires the same and signal generatingreagents (e.g. enzyme substrate) if the label does not generate a signaldirectly. The PMC virus antigen may be already bound to a solid supportor may be provided separately, with reagents for binding it to the solidsupport. Instructions (e.g. written, tape, CD-ROM, etc.) for carryingout the assay usually will be included in the kit.

Immunoassays that utilize PMC virus antigens are useful in screeningsamples (such as blood, serum, plasma, milk, body fluids) to detect ifthe subject from which the tissue was derived has been exposed to orinfected with PMC virus.

The solid support used in the kits of the present invention can includepolymeric or glass beads, nitrocellulose, microparticles, microwells ofa reaction tray, test tubes and magnetic beads.

The signal generating compound can include an enzyme, a luminescentcompound, a fluorophore such as fluorescein, a time-resolved fluorescentprobe such as a europium chelate, a chromogen, a radioactive element, achemiluminescent compound such as an acridinium ester or particles suchas colloidal gold, plain latex, or dyed latex. Examples of enzymesinclude alkaline phosphatase, horseradish peroxidase andbeta-galactosidase.

Kits to Detect Polypeptides and Antigens

The present invention further provides a diagnostic kit for use indetecting the presence of PMC virus proteins.

Accordingly, the invention provides a kit for demonstrating the presenceof PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled polypeptide        derived from the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

Preferably, said antibody is bound to a solid support. The antibody canbe attached to a variety of different solid supports to enable thewashing away of unreacted reagents during the course of using the kit.These include: microwells, coated test tubes, coated magnetic particles,wands or sticks, and membranes (nitrocellulose and others). Preferably,the antibodies are attached to specific locations on a solid substrate.

The anti-PMC virus antibody can be attached to the solid support by avariety of means such as passive adsorption, covalent coupling, or byusing a solid phase pre-coated with a secondary binder such as proteinA, protein G, a secondary antibody specific for the primary antibody,avidin, or an antibody specific for a particular ligand (i.e.: biotin,dinitrophenol, fluorescein, and others). In the case of avidin or any ofthe ligand specific antibodies, it is necessary to covalently attach theligand to the anti-PMC virus antibody.

For example, ELISA kits may be used to detect the presence of antigensto PMC virus in a sample to demonstrate that an animal is suffering fromPMC or is, for example, a non-symptomatic carrier of the virus.

Preferably, the protein to be detected using the present kit is anantigen or an epitope bearing region of a PMC virus protein. Mostpreferably, the antibody binds to the E0, E2, NS2 or NS3 protein of PMC.

Kits to Detect Nucleic Acid Sequences

The invention also provides kits for screening animals suspected ofbeing infected with PMC virus, or to confirm that an animal is infectedwith PMC virus, by detecting PMC virus nucleic acid sequences.

Accordingly, the invention provides a kit for demonstrating the presenceof PMC virus comprising:

-   -   (a) a predetermined amount of at least one labelled nucleic acid        sequence derived from the PMC virus;    -   (b) other reagents; and    -   (c) directions for use of said kit.

For example, the polynucleotide sequence may be one or more primers,such as those exemplified above, and the instructions for use may beinstructions to perform PCR on RNA or DNA extracted from a tissue samplefrom a subject.

Vectors, Host Cells Etc

Vectors

The present invention also provides a recombinant expression vectorcomprising a PMC virus nucleic acid sequence or a part thereof asdefined above, operably linked to prokaryotic, eukaryotic or viraltranscription and translation control elements.

The invention further relates to the hosts (prokaryotic or eukaryoticcells) which are transformed by the above mentioned vectors andrecombinants and which are capable of expressing said RNA and/or DNAfragments.

According to another embodiment the present invention provides methodsfor preparing a PMC virus amino acid sequence, comprising the steps of:

-   -   (a) culturing a host cell containing a vector as described above        under conditions that provide for expression of the PMC virus        amino acid sequence; and    -   (b) recovering the expressed PMC virus sequence.

This procedure can also be accompanied by the step of:

-   -   (c) subjecting the amino acid sequence to protein purification.

The present invention also relates to a method for the production of arecombinant PMC virus polypeptide, comprising the steps of:

-   -   a) transforming an appropriate cellular host with a recombinant        vector, in which a PMC virus polynucleotide sequence or a part        thereof has been inserted under the control of appropriate        regulatory elements,    -   b) culturing said transformed cellular host under conditions        enabling the expression of said insert, and,    -   c) harvesting said polypeptide.

Vectors provided by the present invention will typically comprise a PMCvirus polynucleotide sequence encoding the desired amino acid sequenceand preferably transcription and translational regulatory sequencesoperably linked to the amino acid encoding sequence so as to allow forthe expression of the antigenic polypeptide in the cell. Preferably, thevector will include appropriate prokaryotic, eukaryotic or viralpromoter sequence followed by the PMC virus nucleotide sequences asdefined above. The recombinant vector of the present invention maypreferably allow the expression of any one of the PMC virus polypeptidesas defined above in a prokaryotic, or eukaryotic host or in livingmammals when injected as naked RNA or DNA.

The vector may comprise a plasmid, a cosmid, a phage, or a virus or atransgenic animal. Particularly useful for vaccine development may beBCG or adenoviral vectors, as well as avipox recombinant viruses.Examples of such expression vectors are described in Sambrook et al.,(1989) supra or Ausubel et al., (2001) supra. Many useful vectors areknown in the art and may be obtained from such vendors as Stratagene,New England Biolabs, Promega Biotech, and others.

It may be desirable to use regulatory control sequences that allow forinducible expression of the antigenic polypeptide, for example inresponse to the administration of an exogenous molecule. Alternatively,temporal control of expression of the antigenic polypeptide may occur byonly introducing the polynucleotide into the cell when it is desired toexpress the polypeptide.

It may also be convenient to include an N-terminal secretion signal sothat the antigenic polypeptide is secreted into the cell medium.

Expression vectors may also include, for example, an origin ofreplication or autonomously replicating sequence and expression controlsequences, a promoter, an enhancer and necessary processing informationsites, such as ribosome-binding sites, RNA splice sites, polyadenylationsites, transcriptional terminator sequences, and mRNA stabilisingsequences. Secretion signals may also be included where appropriate,from secreted polypeptides of the same or related species, which allowthe protein to cross and/or lodge in cell membranes, and thus attain itsfunctional topology, or to be secreted from the cell. Such vectors maybe prepared by means of standard recombinant techniques well known inthe art and discussed, for example, in Sambrook et al., (1989) orAusubel et al., (2001).

An appropriate promoter and other necessary vector sequences will beselected so as to be functional in the host, and may include, whenappropriate, those naturally associated with outer membrane lipoproteingenes.

Promoters such as the trp, lac and phage promoters, tRNA promoters andglycolytic enzyme promoters may be used in prokaryotic hosts. Usefulyeast promoters include promoter regions for metallothionein,3-phosphoglycerate kinase or other glycolytic enzymes such as enolase orglyceraldehyde-3-phosphate dehydrogenase, enzymes responsible formaltose and galactose utilization, and others. Vectors and promoterssuitable for use in yeast expression are further described in Hitzemanet al., EP 73,675A. Appropriate non-native mammalian promoters mightinclude the early and late promoters from SV40 or promoters derived frommurine Moloney leukaemia virus, avian sarcoma viruses, adenovirus II,bovine papilloma virus or polyoma. In addition, the construct may bejoined to an amplifiable gene (e.g., DHFR) so that multiple copies ofthe gene may be made.

While such expression vectors may replicate autonomously, they may alsoreplicate by being inserted into the genome of the host cell, by methodswell known in the art.

Expression and cloning vectors will likely contain a selectable marker,a gene encoding a protein necessary for survival or growth of a hostcell transformed with the vector. The presence of this gene ensuresgrowth of only those host cells that express the inserts. Typicalselection genes encode proteins that a) confer resistance to antibioticsor other toxic substances, e.g. ampicillin, neomycin, methotrexate,etc.; b) complement auxotrophic deficiencies, or c) supply criticalnutrients not available from complex media, e.g., the gene encodingD-alanine racemase for Bacilli. The choice of the proper selectablemarker will depend on the host cell, and appropriate markers fordifferent hosts are well known in the art.

Vectors containing PMC virus polynucleotide sequences can be transcribedin vitro and the resulting RNA introduced into the host cell bywell-known methods, e.g., by injection, or the vectors can be introduceddirectly into host cells by methods well known in the art, which varydepending on the type of cellular host, including electroporation;transfection employing calcium chloride, rubidium chloride, calciumphosphate, DEAE-dextran, or other substances; microprojectilebombardment; lipofection; infection (where the vector is an infectiousagent, such as a retroviral genome); and other methods. The introductionof PMC virus polynucleotide sequences into the host cell may be achievedby any method known in the art, including, inter alia, those describedabove.

In a preferred embodiment, the PMC virus polynucleotide is part of aviral vector, such as a baculovirus vector, or infectious virus, such asa baculovirus. This provides a convenient system since not only canrecombinant viral stocks can be maintained and stored until ready foruse. Desirably, the nucleotide sequence encoding the antigenic peptideor polypeptides is inserted into a recombinant baculovirus that has beengenetically engineered to produce antigenic peptide or polypeptides, forinstance, by following the methods of Smith et al (1983) Mol Cell Biol12: 2156-2165. A number of viral transfer vectors allow more than onepolynucleotide sequence encoding a polypeptide to be inserted into thesame vector so that they can be co-expressed by the same recombinantvirus.

Host Cells

To produce a cell capable of expressing PMC virus amino acid sequences,preferably polynucleotide sequences of the invention are incorporatedinto a recombinant vector, which is then introduced into a hostprokaryotic or eukaryotic cell.

The invention also provides host cells transformed or transfected with aPMC virus polynucleotide sequence. Preferred host cells include yeast,filamentous fungi, plant cells, insect, amphibian, avian species,bacteria, mammalian cells, and human cells in tissue culture.Illustratively, such host cells are selected from the group consistingof E. coli, Pseudomonas, Bacillus, Streptomyces, yeast, CHO, R1.1, B-W,L-M, COS1. COS 7, BSC1, BSC40, BMT10, and Sf9 cells.

Large quantities of PMC virus polynucleotide sequence of the inventionmay be prepared by expressing PMC virus polynucleotide sequences orportions thereof in vectors or other expression vehicles in compatibleprokaryotic or eukaryotic host cells. The most commonly used prokaryotichosts are strains of Escherichia coli, although other prokaryotes, suchas Bacillus subtilis or Pseudomonas may also be used. Examples ofcommonly used mammalian host cell lines are VERO and HeLa cells, Chinesehamster ovary (CHO) cells, and WI38, BHK, and COS cell lines, althoughit will be appreciated by the skilled practitioner that other cell linesmay be appropriate.

Also provided are mammalian cells containing a PMC virus polynucleotidesequences modified in vitro to permit higher expression of PMC virusamino acid sequence by means of a homologous recombinational eventconsisting of inserting an expression regulatory sequence in functionalproximity to the PMC virus amino acid sequence encoding sequence.

The invention is not limited to the production of one antigenicpolypeptide at a time in the host cell. Multiple polynucleotidesencoding different antigenic polypeptides of interest may be introducedinto the same host cell. The polynucleotides may be part of the samenucleic acid molecule or separate nucleic acid molecules.

General

Those skilled in the art will appreciate that the invention describedherein is susceptible to variations and modifications other than thosespecifically described. It is to be understood that the inventionincludes all such variations and modifications. The invention alsoincludes all of the steps, features, compositions and compounds referredto or indicated in the specification, individually or collectively andany and all combinations or any two or more of the steps or features.

The present invention is not to be limited in scope by the specificembodiments described herein, which are intended for the purpose ofexemplification only. Functionally equivalent products, compositions andmethods are clearly within the scope of the invention as describedherein.

The entire disclosures of all publications (including patents, patentapplications, journal articles, laboratory manuals, books, or otherdocuments) cited herein are hereby incorporated by reference. Noadmission is made that any of the references constitute prior art or arepart of the common general knowledge of those working in the field towhich this invention relates.

As used herein the term “derived” and “derived from” shall be taken toindicate that a specific integer may be obtained from a particularsource albeit not necessarily directly from that source.

Throughout this specification, unless the context requires otherwise,the word “comprise”, or variations such as “comprises” or “comprising”,will be understood to imply the inclusion of a stated integer or groupof integers but not the exclusion of any other integer or group ofintegers.

Other definitions for selected terms used herein may be found within thedetailed description of the invention and apply throughout. Unlessotherwise defined, all other scientific and technical terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which the invention belongs.

EXAMPLES

The following examples serve to more fully describe the manner of usingthe above-described invention, as well as to set forth the best modescontemplated for carrying out various aspects of the invention. It isunderstood that these methods in no way serve to limit the true scope ofthis invention, but rather are presented for illustrative purposes.

Example 1 Sample Preparation

Tissue samples were extracted and prepared using a method whose mainbasis was derived from Allander et al (2001) “A virus discovery methodincorporating DNase treatment and its application to the identificationof two bovine parvovirus species.” Proc Natl Acad Sci USA. 98(20):11609-14, with some modifications to improve the efficiency from Baughet al (2001) “Quantitative analysis of mRNA amplification by in vitrotranscription.” Nucleic Acids Res. 29(5): E29. However, the methods weremodified to improve efficiency.

1. Preparation of Serum Samples:

-   a) Obtain at least 240 μL of supernatant from a tissue homogenate or    serum and divide into 2×120 ul lots-   b) To each 120 ul of sample add 240 ul of PBS or H₂O (or take 50 ul    sera+100 ul PBS)-   c) Filter diluted sample through two separate 0.2 um filters by    centrifuging at 2000×g (wash top of filter and keep at −20° C.)-   d) Add 25 ul DNASE I (250 U) to each tube of filtered sample and    incubate at 37° C. for 2 hr-   e) Add 1 ul of RNase Cocktail (500 U Rnase A, 20000 U Rnase T1) to    each tube and incubate at RT for 1 hr.-   f) Take 1 tube of treated sample (360 ul) for RNA extraction and one    tube for DNA extraction (add 500 ul DNAeasy AL+50 ul proteinase K    etc and elute in 50 ul water).    2. RNA Extraction:    -   a) Divide sample into 90 ul lots and add 600 ul RLT, ie 4×690 ul    -   b) Homogenize by passing through 21G syringe at least 5×    -   c) Add 690 ul of 70% ethanol to each tube of sample and mix by        pipetting    -   d) Apply 700 ul of sample to column at a time and centrifuge for        15 sec at 10,000 rpm. Place flow through waste in a 5 ml        container and keep at −80° C.    -   e) Add 700 ul of buffer RW1 to the column and centrifuge for 15        sec at 10,000 rpm. Discard flow through material and collection        tube.    -   f) Transfer column to a new tube and add 500 ul of RPE        centrifuge for 15 sec at 10,000 rpm, discard flow through        material    -   g) Repeat step (f) using same tube but centrifuge for 2 min at        10,000 rpm.    -   h) Transfer column to a new tube and centrifuge for 1 min at        10,000 rpm.    -   i) Elute the RNA in 20 ul of RNAse free water, let the water sit        on the column for 1 minute before centrifuging. Reuse the eluate        and centrifuge for 1 min at 10,000 rpm to collect any left over        RNA on column.    -   j) Store RNA at −80° C. until needed.        3. DNA Extraction:-   a) To 360 ul of sample add 36 ul of proteinase K and 360 ul of    buffer AL, mix by vortex, incubate at 70° C. for 10 minutes.-   b) Add 360 ul of 100% ethanol, mix by vortexing-   c) Pipette mixture from step (b) into DNAeasy column and centrifuge    at 8,000 rpm for 1 minute. Place flow-through into a tube and store    at −80° C.-   d) Place column in a new tube and add 500 ul of AW1 spin at 8,000    rpm for 1 minute. Discard flow through and tube.-   e) Place column in a new tube and add 500 ul of AW2 and spin at    13,000 rpm for 3 minutes. Discard flow through and spin for another    1 minute and discard flow through and tube.-   f) Place column in a new tube, add 50 ul of water and let sit for 1    minute. Spin at 8,000 rpm for 1 min and collect eluate. Reapply the    50 ul eluate and spin again.-   g) Store DNA at −80° C. until needed.    RNA Sequence-Independent Single Primer Amplification (SISPA) for    Double Stranded RNA Viruses

The SISPA method employed was developed from that of Baugh et al andAllander et al, to maximise yield and product length while minimisingtemplate-independent side reactions. However, the present method isapplied to low yield viral RNA, not total mRNA and a melting step hasbeen added.

4. First Strand cDNA Synthesis

a) Mix together the following:

-   -   1 ul random hexamers (10 pmol)    -   8 ul-9 ul RNA (in H₂O)        b) Mix, heat 90° C. 3 minutes, spin and put on ice        c) On ice add:

1^(st) strand buffer 4 ul 0.1M dTT 2 ul 5 mM dNTP 2 ul SSIII (400U) 1 ulT4gene32 1 ul1^(St) strand buffer: 50 mM Tris-HCl (pH 8.3), 75 mM KCl, 3 mM MgCl₂d) Mix, spin and heat at 50° C. for 30 minutese) Add another 1 ul of SSIII and leave for another 30 min at 50° C.f) Heat inactivate at 70° C. for 10 minutes and then place on ice5. Second Strand cDNA Synthesisa) On Ice Mix:

H2O 87 ul  5X 2^(nd) strand buffer 30 ul  5 mM dNTPs 6 ul DNA polymerase(40U) 4 ul E. coli DNA ligase (10U) 1 ul RNase H (2U) 2 ul 1^(st) strandDNA mix (step 1) 20 ul 2^(nd) Strand Buffer: 20 mM Tris-HCl (pH 6.9), 4.6 mM MgCl₂, 90 mM KCl,0.15 mM b-NAD⁺, 10 mM (NH₄)₂SO₄b) Mix, spin and incubate at 16° C. for 2 hrs. *NOTE: can start DNASISPA whilst this incubation is underway.*c) Add 10 ul (10 U) T4 DNA polymerase (1 u/ul) and incubate at 16° C.for 15 min.d) Heat 2^(nd) strand synthesis at 72° C. 10 minutes, let cool to 37° C.6. Clean Up DNA

-   a) Spin phase lock at 13,000 rpm for 30 sec at 4° C.-   b) Add 150 ul of step 2 reaction-   c) Add equal volume phenol/chloroform 160 ul-   d) Shake lightly-   e) Spin at 13000 rpm 5 minutes, 4° C.-   f) Transfer upper phase to new tube ˜160 ul-   g) Precipitate DNA add 100% ethanol 2.5V i.e 375 ul and 1 ul    glycogen (20 mg/ml) Leave at −20° C. for 2 hrs or 0/N-   h) Spin at 13000 rpm 20 minutes, remove S/N off pellet-   i) Wash pellet 1×70% ethanol 13000 rpm 5 min at 4° C.-   j) Take pellet up in 35 ul of water *NOTE: can stop here and freeze    at −80° C. until the DNA SISPA sample is also ready.*    DNA SISPA    7. Second DNA Strand Synthesis-   a) Mix together the following:

DNA 50 ul  10 pmol random hexamers (10 pmol/ul) 1 ul 5U 3′-5′ exo Klenowfragment DNA polymerase 1 ul Buffer (supplied with Klenow fragment DNApolymerase) 1 ul 5 mM dNTP 1 ul T4gene32 1 ul

-   b) Leave at 37° C. for 1 hr    8. Clean Up DNA-   a) Spin phase lock at 13,000 rpm for 30 sec at 4° C.-   b) Add 60 ul of step 1 reaction-   c) Add equal volume phenol/chloroform 60 ul-   d) Shake lightly-   e) Spin at 13,000 rpm 5 minutes, 4° C.-   f) Transfer upper phase to new tube ˜60 ul-   g) Precipitate DNA add 100% ethanol 2.5V i.e 150 ul and 1 ul    glycogen (20 mg/ml) Leave at −20° C. for 2 hrs or overnight-   h) Spin at 13,000 rpm for 20 minutes, remove supernatant off pellet-   i) Wash pellet 1×70% ethanol 13,000 rpm 5 min at 4° C.-   j) Take pellet up in 44 ul of water *NOTE: can stop here and freeze    at −80° C. until the RNA SISPA sample is also ready.*    Generation of Recombinant Nucleic Acid Sequences    9. Restriction Digest-   a) Add 10 U Csp 6.1 (i.e 1 ul of 10 U/ul stock) to 35 ul of sample,    add 4 ul of Buffer B and 5 ul of Csp6I-   b) Incubate at 37° C. for 2 hr-   c) Inactivate at 65° C. for 20 minutes    10. Dephosphorylate Digested DNA-   a) To inactivated restriction digest (50 ul) add:    -   6 ul of 10×CIP dephosphorylation buffer    -   0.3 ul of CIP 18 U/ul    -   3.7 ul water        CIP Dephosphorylase buffer 1×: 0.05M Tris-HCl, 0.1 mM EDTA,        pH8.5-   b) Incubate at 37° C. for 30 minutes-   c) Add another 0.3 ul of CIP 18 U/ul and incubate at 37° C. for 30    minutes    11. Clean Up DNA-   a) Spin phase lock at 13,000 rpm for 30 sec at 4° C.-   b) Add 60 ul dephosphorylated DNA-   c) Add equal volume (60 ul) phenol/chloroform-   d) Shake lightly-   e) Spin at 13,000 rpm 5 minutes, 4° C.-   f) Transfer upper phase to new tube ˜50 ul-   g) Precipitate DNA add 2.5 volumes 100% ethanol (150 ul) and 1 ul    glycogen (20 mg/ml) Leave at −20° C. for 2 hrs or overnight-   h) Spin at 13,000 rpm 20 minutes, remove supernatant off pellet-   i) Wash pellet 1×70% ethanol, spin 13,000 rpm 5 min at 4° C.-   j) Dessicate for 2-3 minutes or air dry for 15 minutes-   k) Reconstitute in 5.8 ul H₂O.    12. Adaptor Ligation-   a) Mix together:

T4 DNA ligase (5U/ul) 1.2 ul 5X Ligase Buffer   2 ul 50 pmol adaptor(phosphorylated ends)   1 ul DNA from Step 3. 5.8 ulLigase buffer 5×: 330 mM Tris-HCl, 25 mM MgCl₂, 25 mM DTT, 5 mM ATP, pH7.5

-   b) Incubate 4° C. for 1 hr and 16° C. overnight    13. PCR Reaction (Results FIG. 2)-   a) Set up the following mix:

Ligated DNA (step 4) 2 ul 50 pmol NBam24 1 ul  5 mM dNTP 2 ul  2 mMMgCl2 2 ul 10X PCR Buffer 5 ul H₂O 38 ul 10× PCR buffer: 100 mM Tris-HCl, 500 mM KCl (pH 8.3)b) Heat at 72° C. for 3 minutesc) Add 0.5 ul Taq DNA polymerase (5 U/ul)d) Run cycle:

-   -   72° C. for 5 minutes    -   (94° C. for 1 minute, 72° C. for 3 minutes)×40 hold at 4° C.

-   e) Run 10 ul and 40 ul of product on 1.0% EtBr gel (leave a well    between them to make purification easier)    14. Cloning PCR Product

-   a) Cut out sections of smeared region from gel as a lot of the    dominant bands can be contaminating sequence from the products used    in the methods, rather than the actual sample. Bands can also be    hard to see if they are in the smeared regions.

-   b) Clean up DNA from agarose using the Minielute Gel Extraction Kit    (Qiagen)    -   1. Excise the DNA fragment from the agarose gel with a clean,        sharp scalpel.    -   2. Weigh the gel slice in a colourless tube. Add 3 volumes of        Buffer QG to 1 volume of gel (100 mg ˜100 μl).    -   3. Incubate at 50° C. for 10 min (or until the gel slice has        completely dissolved). To help dissolve gel, mix by vortexing        the tube every 2-3 min during the incubation.    -   4. After the gel slice has dissolved completely, check that the        colour of the mixture is yellow (similar to Buffer QG without        dissolved agarose). Note: If the colour of the mixture is orange        or violet, add 10 μl of 3 M sodium acetate, pH 5.0, and mix. The        colour of the mixture will turn to yellow.    -   5. Add 1 gel volume of isopropanol to the sample and mix by        inverting the tube several times.    -   6. Place a MinElute column in a provided 2 ml collection tube in        a suitable rack.    -   7. To bind DNA, apply the sample to the MinElute column, and        centrifuge for 1 min.    -   8. Discard the flow-through and place the MinElute column back        in the same collection tube.    -   9. Add 500 μl of Buffer QG to the spin column and centrifuge for        1 min.    -   10. Discard the flow-through and place the MinElute column back        in the same collection tube.    -   11. To wash, add 750 μl of Buffer PE to the MinElute column and        centrifuge for 1 min.    -   12. Discard the flow-through and centrifuge the MinElute column        for an additional 1 min at ≧10,000×g (˜13,000 rpm).    -   13. Place the MinElute column into a clean 1.5 ml        microcentrifuge tube.    -   14. To elute DNA, add 10 μl of Buffer EB (10 mM Tris.Cl, pH 8.5)        or H₂O to the centre of the membrane, let the column stand for 1        min, and then centrifuge for 1 min.

-   c) For ligations and cloning use Invitrogen TA Cloning® Kit Version    V 7. Set up the 10 μl ligation reaction as follows:

Fresh PCR product 6 μl 10X Ligation Buffer 1 μl pCR ® 2.1 vector (25ng/μl) 2 μl T4 DNA Ligase (4.0 Weiss units) 1 μl

-   -   Incubate the ligation reaction at 14° C. overnight, or at        −20° C. until you are ready for transformation.

-   d) Transform One Shot® Competent Cells.    -   1. Centrifuge vials containing the ligation reactions briefly        and place them on ice.    -   2. Thaw on ice one 50 μl vial of frozen One Shot® Competent        Cells (enough for 2 ligations).    -   3. Pipette 2 μl of each ligation reaction into 25 ul of        competent cells and mix by stirring gently with the pipette tip.    -   4. Incubate the vials on ice for 30 minutes. Store the remaining        ligation mixtures at −20° C.    -   5. Heat shock the cells for 30 seconds at 42° C. without        shaking. Immediately transfer the vials to ice.    -   6. Add 125 μl of room temperature SOC medium to each vial.    -   7. Shake the vials horizontally at 37° C. for 1 hour at 225 rpm        in a shaking incubator.    -   8. Spread 50 μl to 100 μl from each transformation vial on LB        agar plates containing ˜80 mg/ml X-Gal and 100 μg/ml ampicillin.    -   9. Incubate plates overnight at 37° C. Place plates at 4° C. for        2-3 hours to allow for proper colour development.        15. Screening Colonies for Inserts and Sequencing (Results FIG.        3)

-   a) Use HotStarTaqMaster Mix (50 ul/well of plate):

1X 110X (sufficient for one plate)   25 ul HotStarTaqMaster Mix (vortex)2750 ul 12.5 ul M13-20f (50 pmol) 1375 ul 12.5 ul M13-20f (50 pmol) 1375ul add 50ul per well of the plate

-   -   To make the M13-20f (50 μmol) and M13r (50 μmol) stocks: mix 0.5        ul of 100 uM primer with 12 ul of water i.e 500 ul of 100 uM        stock primer+1200 ul water (from HotStarTaq Kit).

-   b) Place sterile aluminium foil over the plate containing the    HotStar TaqMaster Mix. Stab through the foil to make a hole, and    then stab a bacterial colony into each well of the plate.

-   c) Take off aluminium foil and add strip caps to seal plate.

-   d) Run PCR protocol:    -   95° C. for 15 min    -   (94° C. for 30 s, 50° C. for 30 s, 72° C. for 1 min) X30    -   72° C. for 1 min    -   4° C. hold.

-   e) Run 5-10 ul of PCR on gel

-   f) Use Qiagen Mini elute to clean up the remaining PCR product to    sequence.

Example 2 Enzyme Linked Immunosorbent Assay to Detect Antibodies to PMCVirus

1. Clone and express the PMC virus protein of interest (eg E2, NS3) inbaculovirus and purify the expressed protein. This purified protein canbe used as an antigen to detect specific antibodies to the PMC virusproteins of interest.

2. Coat ‘medium binding’ 96 well microplates (50 uL per well) withantigen diluted in carbonate buffer (0.05M Carbonate buffer 1× (pH 9.6):Na₂CO₃ (1.59 gm); NaHCO₃ (2.93 gm) water to 114 Hold overnight at roomtemperature (18-25° C.).

3. Dilute samples and controls (Negative, High and Low Positive) 1/100in sample diluent (phosphate buffered saline (pH 7.3) solutioncontaining 1% skim milk powder and 0.05% Tween 20).

4. Wash plates 5 times with PBS-Tween and tap to dry.

5. Transfer diluted samples and controls to the ELISA plate induplicate: 50 uL to each well.

6. Incubate at 37° C. for 1 hr in a humidified container.

7. Wash plates 5 times with PBS-Tween, rotate and wash 5 more times,then tap to dry.

8. Dilute conjugate (antiporcine IgG, horseradish peroxidase conjugated)in sample diluent and add 50 uL to each well.

9. Incubate at 37° C. for 1 hr in a humidified container.

10. Wash plates 10 times with PBS-Tween, then 5 times with purifiedwater.

11. Develop by adding 100 uL of TMB substrate to each well. Incubate at37° C. in the dark for about 10 min until target OD is achieved forcontrols. A commercially available TMB substrate can be used (eg.Boehringer Mannheim Corp., Pierce Chemical Co., and Kirkegaard & PerryLaboratories).12. Stop by adding 100 uL of 1M sulphuric acid.13. Read OD values at 450 nm.14. Calculate results.

Example 3 Enzyme Linked Immunosorbent Assay to Detect Antigens of PMCVirus

It should be noted that working solutions of the detector reagent andenzyme conjugate reagents should be made within approximately 1 hour ofanticipated use and then stored at 4° C.

Materials

ELISA Wash Buffer—10× concentrate: 1 M Tris; HCl (6.25 Normal) for pHadjustment; 0.01% Thimerosal; and 5% Tween 20.

Detector Reagent—10× concentrate: 25% Ethylene Glycol, 0.01% Thimerosal,approximately 5% biotinylated goat anti-PMC virus antibody, and 0.06%yellow food colouring in PBS (pH 7.4). The working Detector Reagent isprepared by mixing 1 part of the Detector Reagent—10× concentrate, 1part of NSB Reagent 10× concentrate, and 8 parts of Reagent DiluentBuffer. This working agent should be prepared within approximately 1hour of anticipated use.

NSB Reagent—10× concentrate: 25% Ethylene Glycol, 0.01% Thimerosal, 0.2%Mouse IgG, 0.06% red food colouring in PBS (pH 7.4).

Reagent Diluent Buffer: 2.5% Bovine Serum Albumin, 0.01% Thimerosal, and1.0% bovine gamma globulin in PBS (pH 7.4).

Enzyme Conjugate Reagent—10× concentrate: 25% Ethylene Glycol, 0.01%Thimerosal, streptavidin-biotinylated horseradish peroxidase complex(dilution approximately 1 to 700), 0.1% rabbit albumin, and 0.02% rabbitgamma globulin in PBS (pH7.4). Working Enzyme Conjugate Reagent shouldbe prepared by mixing 1 part of Enzyme Conjugate Reagent—10×concentrate, 1 part of NSB Reagent—10× concentrate, and 8 parts ofReagent Diluent buffer. This working reagent should be prepared withinapproximately 1 hour of anticipated use.

Negative Control: 1% Igepal, and 0.01% Thimerosal in PBS (pH 7.4).

Positive Control: 1% Igepal, 0.01% Thimerosal, 1% Bovine Serum Albumin,PMC virus culture (dilution approximately 1:20) and 50 μM phenyl methylsulfonyl fluoride in PBS (pH7.4).

Method

1. Prepare specimens by standard methods. For samples containing cells(tissues, white blood cells) homogenise the tissue and add sample lysisbuffer (1% NP40). Allow at least 1 hour for antigen extraction and mixcontinually.

2. Clarify specimens by centrifuging for 15 minutes at approximately2000 g;

3. Coat 96 well microplates with purified polyclonal antiserum raisedagainst PMC virus antigens (100 uL/well). Alternatively, a mixture ofanti-PMC virus monoclonal antibodies may be used. Each 96-well tray iscoated overnight at room temperature with 0.1 ml per well of a solutioncontaining purified antibody at 5 μg/ml and bovine serum albumin at 10μg/ml in carbonate buffer (pH9.6). Following the coating, each tray iswashed three times with ELISA wash buffer and allowed to dry overnightat 4° C. A foil pouch is used to encase each tray after drying, and adesiccant is included inside each pouch to remove moisture.4. Wash ELISA plates 3 times by pipetting 0.2 ml of ELISA Wash Bufferinto each well and tap or pipette dry prior to the addition of sample.5. Block ELISA plates with Blocking solution 1 (200 uL/well) for 30 minat 37° C. in a humidified container.6. Transfer 100 uL of each specimen (including controls) to the ELISAplate;7. Incubate plates for 60 min at 37° C. in a humidified container;8. Wash ELISA plates 5 times with ELISA Wash Solution;9. Block ELISA plates with Blocking Solution 2 (150 uL) for 30 min at37° C. in a humidified container; 10 Wash ELISA plates 5 times;11. Add Detector Reagent containing biotinylated anti-PMC virusmonoclonal antibody (100 uL) to all wells;12 Incubate plates for 60 min at 37° C. in a humidified container;13 Wash plates 5 times;14. Add Enzyme Conjugate Reagent containing streptavidin-biotinylatedhorseradish peroxidase complex and add 100 uL to all wells;15. Incubate plates for 30 min at 37° C. in a humidified container;16. Wash plates 10 times;17. Prepare and add 100 uL of TMB substrate solution to all wells. Acommercially available TMB substrate may be used (eg. BoehringerMannheim Corp, Pierce Chemical Co, and Kirkegaard & Perry Laboratories).18. Incubate plates for approx 10 min at room temperature in the dark;19. Stop reaction with 1M sulphuric acid (100 uL per well);20. Read ODs on ELISA plate reader at 450 nm;21. Calculate results.

Example 4 Detection of PMC Virus RNA by Reverse Transcriptase (RT)Polymerase Chain Reaction (PCR)

a) Extract RNA from the test specimen as described in Example 1. Includein all steps of the reactions known positive and negative controls and a‘blank’.

b) Reverse transcribe (RT) the RNA as follows:

-   -   1. Mix together the following:

random hexamers (50 pmol) 1 ul RNA (in H2O) 9 ul

-   -   2. Heat at 90° C. for 3 minutes, spin and put on ice    -   3. On ice add:

1st strand buffer 4 ul 0.1M dTT 2 ul 5 mM dNTP 2 ul SSIII (200U) 1 ul

-   -   4. Mix, spin heat at 45° C. for 60 minutes.    -   5. Heat inactivate at 70° C. for 10 minutes    -   6. Place on ice.        c) Set up 1st round PCR    -   1. Mix together the following PCR reagents

RT 5 ul Forward primer 4 uM 1 ul Reverse primer 4 uM 1 ul Hotstart PCRmix (Qiagen) 12.5 ul   Water 5.5 ul  

-   -   -   (see Table 3 for 1st reaction PCR primers)

    -   2. Cycle the PCR machine at:        -   95° C. for 15 minutes        -   (94° C. for 30 sec, 50° C. for 30 sec, 72° C. for 1 min)×40        -   72° C. for 1 min        -   4° C. hold            d) Set up Nested PCR

    -   1. Mix together the following PCR reagents:

1st PCR product 1 ul Forward nested primer 2 0uM 1 ul Reverse nestedprimer 2 0uM 1 ul Hotstart PCR mix (Qiagen) 12.5 ul   Water 9.5 ul  

-   -   -   (see Table 3 for nested PCR primers. If no nested primer is            listed, use 1st PCR primer)

    -   2. Cycle the PCR machine at        -   95° C. for 15 minutes        -   (94° C. for 30 sec, 50° C. for 30 sec, 72° C. for 1 min)×25        -   72° C. for 1 min        -   4° C. hold            e) Run 5 ul of nested PCR product on a 1.5% ethidium bromide            gel for 1 hour. Depending on the primers used, the expected            size of the product is as listed in Table 1.

TABLE 3 Primers for PCR detection of PMC virus SEQ *PrimerPrimer Sequence ID Nested Clone Virus name (5′ to 3′) NO Product CR3 9Pestivirus CR39F (63) CACATCTAGCAGCAGACTATGA 28 103 bp CR39R (190)GTACCAGTTGCACCACCC 29 CR39FN (87) TGAAAAGGATTCACGG 30 ER5 10 PestivirusER510F (7) AAACCGACGAAGTAGACC 31 114 bp ER510R (213) AGACGAGAACATAGTGGC32 ER510FN (68) GAAACAGTAAAGCCAACG 33 ER510RN (182) CTGGTAATCGGAAACATC34 ER6 2 Pestivirus ER62F (203) GGGACCGAGGGATACGA 35 98 bp ER62FN (373)AGAGGTAATTGGGTAT 36 ER62R (637) CAGCAGGTTGATTTCTTCAT 37 ER62RN (516)TTGCCAAGTTTCAC 38 ER5 5 Pestivirus ER55F (31) AAACCGCCGAAGTAAACC 39143 bp ER55R (214) CTGGAGCCCTGGTAATGG 40 ER55FN (64) GACGGGAATGGGTTCA 41ER55RN (162) TAGGTGCTTCTTATTGGTAT 42 *F = forward primer, R = reverseprimer, FN = forward nested primer, RN = reverse nested primer

Example 5

Determination of Full Length Viral Sequence

Once the authenticity of the presence of PMC virus sequence has beenconfirmed in a sample by PCR, the entire viral sequence can be acquiredby designing PCR primers to span the gaps between the clones (refer toTable 4). RT-PCR was carried out as either a two step (RT then PCR) orone step RT-PCR reaction.

1. RT Reaction:

a) Mix together the following:

-   -   1 ul random hexamers (50 μmol)    -   4 ul RNA    -   4 ul Rnase free water        b) Heat 70° C. 10 minutes, spin and put on ice        c) On ice add    -   4 ul 1st strand buffer    -   2 ul 0.1M dTT    -   2 ul 5 mM dNTP    -   2 ul SSIII (400 U)        d) Mix, spin heat at 42° C. for 60 minutes.        e) Heat inactivate at 70° C. for 10 minutes        f) Place on ice        2. PCR Reaction:        a) Mix together the following PCR reagents

RT 1 ul Forward primer 20 uM 1 ul Reverse primer 20 uM 1 ul Hotstart PCRmix (Qiagen) 12.5 ul   Water 13.5 ul  

-   -   (see Table 4 for PCR primers)        b) Cycle the PCR machine at:    -   95° C. for 15 minutes    -   (94° C. for 30 sec, 47° C. for 30 sec, 72° C. for 2 min)×40    -   72° C. for 1 min    -   4° C.—hold        3. One Step RT-PCR Method        a) Mix Together the Following Reagents from the SSIII RT-PCR Kit

2x reaction mix   25 ul Forward primer 30 uM   1 ul Reverse primer 30 uM  1 ul SSIII RT/Platinum mix   2 ul for products 2.5 kb or less   4 ulfor products 2.5 kb or more Water 15.8 ul for products 2.5 kb or less13.8 ul for products 2.5 kb or more

-   -   (see Table 4 for PCR primers)        b) Cycle the PCR machine at:    -   50° C. for 50 minutes    -   94° C. for 2 min    -   (94° C. for 15 sec, 50° C. for 30 sec, 68° C. for 1 min/kb)×40    -   68° C. for 5 min    -   4° C.—hold

RT-PCR product of interest was PCR spin cleaned and cloned into theInvitrogen TA cloning vector PCR2.1 (see Example 1). Positive cloneswere then identified and sent for sequencing, as described in Example 1.

The primers used for sequencing were M13r, m13-20, primers in Table 4and primers designed specifically for sequencing (see Table 5).

Plasmid sequence, PCR primers and poor sequence reads were removed fromthe sequence before being used in the program Bioedit (Hall, T. A.(1999) BioEdit: a user-friendly biological sequence alignment editor andanalysis program for Windows 95/98/NT. Nucl. Acids. Symp. Ser.41:95-98.). Bioedit allowed the construction of contigs and theproduction of the full length consensus sequence for the virus.

TABLE 4 Primers designed to PCR the gaps between the SISPA clonessequences SEQ Region to Primer Sequence ID Product PCR *Primer names (5′to 3′) NO size 5′UTR-Erns JFP1F CATGCCCATAGTAGGAC 43 1338 bp JFRR3RACCAGTTRCACCAMCCAT 44 Erns-P7 CR39-Er55PCRF AGGGCTCTCACATGGTTGTC 451810 bp ER55-510-512 R CCATTACCAGGGCTCCAG 46 Erns-NS5A CR39F(63)CACATCTAGCAGCAGACTATGA 47 2349 bp ER55RN(162) TAGGTGCTTCTTATTGGTAT 48P7-NS5A ER55-510-512 F CGTTGGCTTTACTGTTTCATTG 49 5560 bp CR316-CR24RTCCCCGAAGCTTGGTTTAAT 50 NS3-NS5A NS3F GTCAGGCCTGCCTATCTTTG 51 4431 bpCR316-CR24R TCCCCGAAGCTTGGTTTAAT 52 NS5A-NS5B CR316-CR24FCGGGACCATTAAACCAAGC 53 2440 bp ER62-ER63R CAGGGGGTTCCAAGAATACA 54 *F =forward primer, R = reverse primer

TABLE 5 Primers designed for sequencing Protein SEQ location *PrimerPrimer Sequence ID of primer names (5′ to 3′) NO 5 UTR 5utr(140)RGGTGTACTCACCGCTTAGCC 55 NPRO NPRO(630)RS TTGCTACAATCGCCCTTCTT 56 NPRONPRO(779)FS AGGGAGAATGACAGGGTCTG 57 Capsid capsid(927)FSACAAAGGAGCAAAACCCAAG 58 ERNS EO(1365)RS GTCACGTTGGTGGACCCTAC 59 E1E1(2402)RS AGCCAGAAATGCCACAGC 60 E1 E1(2606)FS ACCTGTGTGGGTGCTAACAT 61E2 E2(3086)RS TTACTTTGTCTTCCCGTTGC 62 NS2 NS2(4409)FSCCAAGAAACTTCCCCATACG 63 NS2 ns2(4460)RS TTCCACATCCTCTTTCTTCTTTT 64 NS3NS3(5170)RS GCTGGCCCTCGAATGATCCA 65 NS3 NS3(5468)FS GTTCCCTGTGTCCTTGCTGA66 NS3 NS3(5670)RS TGTTTTTGTCTTGGCACTGG 67 NS3 NS3(6296)FSGAGCACAACAGGGCAGAAAT 68 NS3 NS3(6479)RS CCATCTTCCTTGTAGGCACA 69 NS3NS3F(6525)F GTCAGGCCTGCCTATCTTTG 70 NS3 NS3(7153)FS GGAGAAGTCACTGACGCACA71 NS3 NS3(7241)RS GCCATTTCAATCCCAGTATG 72 NS4B NS4B(7715)FSGGGGTCCACACAGCATTGTA 73 NS4B NS4B(7893)RS CCCTTGATACTCACGCCTGT 74 NS4BNS4B(8532)FS GCCGACTCAAAATGGAGAAA 75 NS5A NS5A(8810)RSGCCACCCTATTCTTGGATCTC 76 NS5B NS5B(10889)FS AAATGAGAAGAGGGCAGTGG 77 NS5BNS5BF-10936 AAGGCCACCACTCAAATCAC 78 NS5B NS5BR-12039AGGCTTCTGCTTGACCCAGT 79 *FS = forward primer, RS = reverse primer NOTE:Numbers in brackets are estimated locations on Reference pestivirusstrain NADL.

Example 6 UTR Sequences

5′RACE and 3′Race were used to aquire the 5′UTR and 3′UTR sequences.

5′ RACE Method

Sequence data from the complete 5′ untranslated region (UTR) wasgenerated using rapid amplification of cDNA ends (RACE, BD), asdescribed by BD Biosciences Clonetech with the following modifications.PMC virus-specific primer CR24R (5′TCCCCGAAGCTTGGTTTAAT3′, SEQ ID NO:80) was used to generate the cDNA. Hotstart PCR (Qiagen) was carried outwith primers CR39R (Table 3) and BD Universal primer A mix (5′CTAATACGACTCACTATAGGGCAAGCAGTGGTATCAACGCAGAGT3′, SEQ ID NO: 81; and5′CTAATACGACTCACTATAGGGC3′, SEQ ID NO: 82) with an annealing temperatureof 67° C. and extension time of 2 minutes. The PMC virus specific primerN^(Pro)(630)RS (Table 5) and BD nested Universal Primer A(5′AAGCAGTGGTATCAACGCAGAT3′, SEQ ID NO: 83) were used for the HotstartNested PCR, with an annealing temperature of 55° C. and an extensiontime 2 minutes. Nested PCR products were cleaned, cloned and sequenced.

2. 3′ RACE Method

Sequence data from the complete 3′ untranslated region was generated byfirst adding a poly (A) tail to the viral RNA, using Epicentre's A-PlusPloy(A) polymerase tailing Kit for 8 minutes. This was followed by rapidamplification of cDNA ends (RACE, BD), as described by BD BiosciencesClonetech with the following modifications. Hotstart PCR (Qiagen) wascarried out with primers ER62F (Table 3) and BD Universal primer A mix(5′ CTAATACGACTCACTATAGGGCAAGCAGTGGTATCAACGCAGAGT3′, SEQ ID NO: 84; and5′CTAATACGACTCACTATAGGGC3′, SEQ ID NO: 85) with an annealing temperatureof 65° C. and extension time of 2 minutes. The PMC virus specific primerNS5B(12100)F (Table 5) and BD nested Universal Primer A(5′AAGCAGTGGTATCAACGCAGAT3′, SEQ ID NO: 86) were used for the HotstartNested PCR, with an annealing temperature of 65° C. and an extensiontime 2 minutes. Nested PCR products were cleaned, cloned and sequenced.

Example 7 Real Time PCR

The following primers and a matching probe based on Taqman® technologywere developed:

Forward primer: (SEQ ID NO: 87) CAGTTGGTGTGATCCATGATCCT Reverse primer:(SEQ ID NO: 88) GGCCTCACCCTGCAACTTT Probe: (SEQ ID NO: 89)6FAM-AAGTCTTCAGCAGTTAACT-MGBNFQ

6FAM=6 carboxyfluorescein; MGBNFQ=“minor groove binder non-fluorescencequencher.” Similar primer/probe combinations may be developed for othersegments of the PMC genome.

-   -   A Real Time PCR assay was carried out using the following steps:    -   a) Extract RNA from the test specimen. Include in all steps of        the reactions known positive and negative controls and a        ‘blank’.    -   b) Prepare reaction mixture (volumes per sample) as follows:

2x Mastermix (Roche) 12.5 uL   40x Multiscribe 0.625 uL    Forwardprimer 1 uL Reverse Primer 1 uL Taqman Probe 1 uL Template (sample) 2 uLWater 6.875 uL   

-   -   c) Set up cycling conditions for the PCR cycler available (the        cycles below are appropriate for a Cepheid Smartcycler)        -   Cycle the PCR machine at:            -   Stage 1: Repeat 1×                -   48° C. for 30 min                -   95° C. for 10 min            -   Stage 2: Repeat 45×                -   95° C. for 15 secs                -   58° C. for 30 secs each    -   d) Determine results using the Smartcycler software using        cycle-threshold (CT) values. A CT value of <35 is considered to        be positive. Values between 35-40 are suspicious and values>40        are negative.

Example 8 Production of Recombinant Baculoviruses and Expression ofRecombinant PMC Virus Proteins

1. Cloning of PCR Fragments

PCR products are purified with PCR SPINCLEAN™ columns (ProgenIndustries, Limited), according to the manufacturer's instructions. Ifthe PCR reaction produces non-specific bands in addition to the requiredproduct, or subcloning from another plasmid was necessary, the DNA canbe further purified by elution from a 0.8% agarose gel, using amodification of the method described by Heery (1990).

Purified PCR fragments are digested and ligated into pBlueBacHis A, B orC baculovirus transfer vectors (MaxBac Baculovirus Expression System,Invitrogen Corporation) containing compatible cohesive overhangs, usingstandard cloning protocols (Sambrook et al., 1989; Current Protocols inMolecular Biology, 1991). A, B or C vectors provide three differentreading frames to achieve protein expression in the baculovirusexpression system.

2. Transformation of Baculovirus Plasmids with the PCR Fragments

The ligations are transformed into competent E. coli strain Top 10(Invitrogen Corporation), Genotype: FmcrA D(mrr-hsdRMS-mcrBC)f80lacZDM15 DlacX74 deoR recA1 araD139 D(ara-leu)7697 galU galK rpsLendA1nupG, and/or Sure® E. coli (Stratagene), Genotype: e14⁻(McrA⁻)D(mcrCB-hsdSMR-mrr) 171 endA1supE44 thi-1 gyrA96 rel A1 lac recB recJsbcc umuc::Tn5 (kan^(r)) uurC[F′ proAB lacI^(a)Z D m15 Tn10(Tet^(r))]°.Protocols for the preparation of competent cells and transformation ofthe bacteria are taken from the Invitrogen MaxBac Baculovirus ExpressionSystem Manual Version 1.8.

Screening bacterial clones for plasmid containing PCR fragment andplasmid purification for transfection

Bacterial clones containing pBlueBacHis+PCR fragment are identified bygrowing colonies, extracting the plasmids using the boiling miniprepmethod described in Sambrook, et al. (1989), and then undertakingrestriction digests of the plasmids to verify those containing thecorrect-sized insert. Recombinant plasmids are purified to a levelsuitable for transfection reactions using plasmid purification kits(QIAGEN Pty Ltd., tip-20 or tip-100 columns), according to themanufacturer's instructions.

3. Production of Purified Recombinant Baculoviruses by Cationic LiposomeTransfection of Sf9 Cells to Produce Recombinant Baculoviruses

Recombinant baculoviruses are produced by co-transfecting linearisedwild-type Autographa californica nuclear polyhedrosis virus (AcMNPV) DNAand baculovirus transfer vector containing PCR fragment into Sf9 cells,by the technique of cationic liposome mediated transfection. This iscarried out according to the Invitrogen MaxBac Baculovirus ExpressionSystem Manual Version 1.8.

4. Plaque Purifying Recombinant Baculoviruses

Recombinant virus is plaque purified three times before virus masterstocks are prepared, ensuring the virus is cloned from a single particleand no wild-type virus is present. Plaque assays are set up accordingthe Invitrogen MaxBac Baculovirus Expression System Manual Version 1.8.

After each round of plaque purification, the recombinant viruses arescreened using a modified Pestivirus antigen-capture ELISA (PACE)(Shannon et al., 1991). The modified method involves supernatant+cells(50 μl/well) being added directly to a blocked, washed ELISA plate, andthe plate incubated for 1 hr at 37° C. Antibody solution (50 μl/well) isthen added. The antibody used is either biotinylated goatanti-pestivirus antiserum or individual anti-PMC virus monoclonalantibodies (mAbs). The plate is incubated overnight at 22° C., thendeveloped as described by Shannon et al. (1991), omitting the incubationwith biotinylated anti-mouse IgG for samples that are reacted with thebiotinylated goat antiserum.

5. Recombinant Baculovirus Master, Seed and Working Stocks

The master virus stock for each of the recombinant baculovirusesconstructed are made according the Invitrogen MaxBac BaculovirusExpression System Manual Version 1.8. The titre of the stock isdetermined by a plaque assay, as described above, except that the cellsare overlaid with 1.5% carboxymethylcellulose (CMC, BDH; 6% CMC indeionised water, diluted 1 in 4 with complete TC100+X-gal [125 μg/ml,Boehringer Mannheim]). After 7 days, the blue plaques are counted togive the virus titre.

The seed and working stock are made from the master and seed stock,respectively using a low MOI of 0.1 to 0.5 pfu/ml. All virus stocks arestored at 4° C. for use in vaccine production. For long term storage ofMaster, Seed and Working stocks, each recombinant virus is ampouled andfrozen at −80° C.

6. Optimisation of Recombinant Protein Production

Sf9 insect-cell suspensions, adapted to Sf-900 II Serum Free Mediaaccording to the protocol described by Gibco BRL (1995), are used tooptimise recombinant protein expression. Two conical flasks, containing50 ml cells (1.5×10⁶ cells per ml), are infected with recombinantbaculovirus at a high and low MOI, between 0.1 and 5.0. A third flaskacts as an uninfected control culture. The 3 flasks are incubated withshaking at 28° C., and 5 ml aliquots removed at 24 hr intervals for upto 7 days.

The samples are centrifuged at room temperature (RT) for 10 min at900×g, and the supernatants carefully removed. The pellets andsupernatants are stored at −20° C. until daily sampling is completed.The amount of specific, recombinant pestivirus protein in the samples isthen determined using the modified PACE described above. The cellpellets are reconstituted in 200 μl or 250 μl NP-40 (1% [v/v] in PBS),vortexed and centrifuged at RT for 10 min at 900×g. Serial dilutions ofthe pellet extract (in 1% [v/v] NP40) are assayed. The culturesupernatants are assayed undiluted, as well as serially diluted (in 1%[v/v] NP40). If cell viability is reduced at a higher rate of infection,then an MOI or 0.1 to 2 is more appropriate.

Modifications of the above-described modes of carrying out the variousembodiments of this invention will be apparent to those skilled in theart based on the above teachings related to the disclosed invention. Theabove embodiments of the invention are merely exemplary and should notbe construed to be in any way limiting.

What is claimed is:
 1. An isolated RNA or DNA nucleotide sequencecomprising: a) an RNA or DNA sequence having at least 98% identity withSEQ ID NO: 11, wherein when the isolated RNA or DNA nucleotide sequenceis an RNA nucleotide sequence, thymidine (t) nucleotides are substitutedwith uridine (u) nucleotides; b) an RNA or DNA sequence having at least95% sequence identity with SEQ ID NO: 11; or c) an RNA or DNA sequencehaving at least 90% sequence identity with SEQ ID NO: 11; or d) an RNAor DNA sequence comprising the complement of the nucleotide sequence of(a) or (b) or (c).
 2. A method for detecting the presence or absence ofporcine myocarditis syndrome (PMC) virus in a biological sample,comprising the steps of: a) bringing the biological sample into contactwith a polynucleotide probe or primer comprising an isolated RNAnucleotide sequence according to claim 1 under suitable hybridizingconditions; and b) detecting any duplex formed between the probe orprimer and nucleic acid sequences in the sample.
 3. A method for thedetection of PMC virus nucleic acids present in a biological sample,comprising: a) amplifying the RNA or DNA nucleotide sequence of claim 1with at least one primer, and b) detecting the amplified nucleic acids.4. A method for the detection of PMC virus nucleic acids present in abiological sample, comprising: a) hybridizing the nucleic acids of thebiological sample at appropriate conditions with one or more probescomprising an isolated RNA or DNA nucleotide sequence according to claim1, b) washing under appropriate conditions, and c) detecting the hybridsformed.
 5. A method for detecting viral RNA or DNA comprising the stepsof: a) immobilizing PMC virus on a support; b) disrupting the virion;and c) hybridizing the nucleic acids of the virion with a probecomprising an isolated RNA or DNA nucleotide sequence according toclaim
 1. 6. A method for screening the tissue of subjects for PMC viruscomprising the steps of: a) extracting DNA from tissue; b) restrictionenzyme cleavage of said DNA; c) electrophoresis of the fragments; and d)Southern blotting of genomic DNA from tissues and subsequenthybridization with a labelled cloned PMC virus DNA sequence according toclaim
 1. 7. An immunogenic composition comprising an isolated RNA or DNAnucleotide sequence according to claim
 1. 8. A vector comprising: (a) anisolated polynucleotide sequence encoding a PMC virus comprising anisolated RNA or DNA nucleotide sequence according to claim 1; and (b) aheterologous polynucleotide.
 9. The vector of claim 8 wherein theheterologous polynucleotide is operably linked to the polynucleotidesequence of the PMC virus, such that expression of the polynucleotidesequence of the PMC virus also leads to expression of the heterologouspolynucleotide sequence.
 10. The vector of claim 8, wherein the PMCvirus expressed from said vector is attenuated.
 11. A kit fordemonstrating the presence of PMC virus comprising: (a) a predeterminedamount of at least one labelled nucleic acid sequence derived from thePMC virus, wherein said nucleic acid sequence comprises an isolated RNAor DNA nucleotide sequence according to claim 1; and (b) directions foruse of said kit.
 12. A recombinant expression vector comprising anisolated RNA or DNA nucleotide sequence of claim 1, operably linked toprokaryotic, eukaryotic or viral transcription and translation controlelements.
 13. An isolated host cell transformed by the vector of claim12.
 14. A method for preparing a PMC virus amino acid sequence encodedby an isolated RNA or DNA nucleotide sequence according to claim 1,comprising the steps of: (a) culturing a host cell containing a vectoraccording to claim 12 under conditions that provide for expression ofthe PMC virus amino acid sequence; and (b) recovering the expressed PMCvirus sequence.
 15. The composition of claim 7 wherein the compositionfurther comprises a pharmaceutically acceptable carrier or diluentand/or an adjuvant.
 16. A method of inducing an immune response in ananimal comprising the steps of: providing an immunogenic compositionaccording to claim 7 to the animal in an amount effective for producingan immune response.
 17. The method of claim 16 wherein the immunogeniccomposition is administered by a method selected from the groupconsisting of: intravenously, subcutaneously, intramuscularly,intraorbitally, ophthalmically, intraventricularly, intracranially,intracapsularly, intraspinally, intracisternally, intraperitoneally,buccal, rectally, vaginally, intranasally, orally and aerosoladministration.
 18. A method for preparing a PMC virus amino acidsequence, comprising the steps of: (a) culturing a host cell containinga vector according to claim 12 under conditions that provide forexpression of the PMC virus amino acid sequence; and (b) recovering theexpressed PMC virus sequence.